Regardless you are using local set or US set, this tablet is covered under Asus International Warranty, just bring your warranty card/receipt to Asus Service Centre and tell them your problem.

KUALA LUMPUR
ASUS Service Center – Kuala Lumpur
4-010 (4th Floor), Plaza Low Yat,
Jalan Bintang, Off Jalan Bukit Bintang,
Bukit Bintang Central, 55100 Kuala Lumpur
Tel : 03-21100842
Operating hours : Monday – Sunday (10:00am to 10:00pm)

PENANG
ASUS Service Center – Penang
1-02-05 E-gate,
Lebuh Tunku Kudin 2,
11700 Gelugor, Penang
Tel : 04-659-6780 / 782
Operating hours : Monday – Friday (10:00 am to 7:00pm) (except Public Holiday)

JOHOR
ASUS Authorized Service Center
IT Plaza Sdn Bhd. IT Service Centre,
04-15, Level 4, Skudai Parade,
Jalan Skudai, 81300 Skudai, Johor
Tel : 07-5544-000
Operating hours : Monday – Friday (10:00 am to 7:00pm) (except Public Holiday)

SARAWAK
ASUS Service Center – Sarawak
Unit 4.4, Level 4, LOT 14665,
ONEJ-ICT SHOPPING COMPLEX,
Jalan Stutong, 93350 Kuching, Sarawak
Tel : 082-457-612
Operating hours : Monday – Friday (10:00 am to 7:00pm) (except Public Holiday)

SABAH
ASUS Service Center – Sabah
Lot 3.04, 3rd Floor,
Block C, Kompleks Karamusing,
Jalan Tunku Abdul Rahman, 88000,
Kota Kinabalu, Sabah
Tel : 088-210-650
Operating hours : Monday – Friday (10:00 am to 7:00pm) (except Public Holiday)

1 year under Asus International Warranty Policy. If you buy from Senheng/SenQ, you are getting additional 1 year warranty under them.

Yes, it is better for you to relock your bootloader and unroot your device before sending for warranty purpose, but there are some forumers here say some Asus Service Center honors the warranty regardless the status of the device as long as the proof of purchase and related info is in the system, but better safe than sorry.

You can use toolkit to finish the job for you, please refer Post#3 for the toolkit download link.

There are few ways to do this, the easy ways should be using the toolkit from the following authors:

Windows User:
1. Wug’s Nexus Toolkit [Click Me]
2. Mskip’s Nexus Toolkit [Click Me]

Mac User:
1. Mac Toolkit [Click Me]

As this is a Nexus device, there are many custom ROMs out there in XDA forum, here are few popular custom ROMs that you can try, but before you start flashing it, please check if the ROM that you are going to use is compatible with LTE(deb) version or not, else you won’t have radio after all.

1. CyanogenMod [Click Me]
2. Paranoid Android [Click Me]
3. AOKP [Click Me]
4. Carbon ROM [Click Me]
5. SlimBean [Click Me]

and many more, please refer XDA forum for more downloads. [XDA Forum link]

Normally custom kernel comes with custom ROM, but you can always override the current kernel with new kernel, but please check if the kernel supports your current ROM because some of them are AOSP based and might cause issue with CM based ROM. Also please check if the kernel is compatible with LTE(deb) version or not else you might brick your device.

1. ElementalX [Click Me]
2. Franco’s kernel [Click Me]
3. Glitch kernel [Click Me]

and many more, please refer XDA forum for more downloads. [XDA Forum link]

Yes, use MultiROM.
MultiROM is one-of-a-kind multi-boot mod for Nexus 7. It can boot any Android ROM as well as other systems like Ubuntu Touch, once they are ported to that device. Besides booting from device's internal memory, MultiROM can boot from USB drive connected to the device via OTG cable. The main part of MultiROM is a boot manager, which appears every time your device starts and lets you choose ROM to boot. You can see how it looks on the left image below and in gallery. ROMs are installed and managed via modified TWRP recovery. You can use standard ZIP files to install secondary Android ROMs and MultiROM even has its own installer system, which can be used to ship other Linux-based systems.

Installation instructions and download link: [Click Me]

You may want to do this when you are sending back your device for warranty purpose, use the toolkit posted above to do it.

Here you go [Click Me]

Please download the correct factory image, there are 2 versions, one is for WiFi model and another one is for WiFi + LTE model.
WiFi model only – razor
WiFi + LTE model – razorg

Here are few popular cover and casing for Nexus 7 (2013).
1. Nexus 7 (2013) Folio Case by Google
Convenient and functional protection for your Nexus 7.

Available in Red and Black color.
Buy from US Google Play, not available in Malaysia set, but look out for Garage Sales section as forumers are bringing in from US directly.

2. Nexus 7 (2013) Case by Google
The first tablet case designed by Google specifically for the Nexus 7. Using the built-in stand, you can easily type an email, get on a Hangout, or watch the latest and greatest monkey-washing-a-cat video. We won’t judge.

Available in Grey/Red, White/Red, Gray/Blue and Black color.
Buy from US Google Play, not available in Malaysia set, but look out for Garage Sales section as forumers are bringing in from US directly.

3. Nexus 7 (2013) Travel Cover by Asus
Your Nexus 7 goes further with light and convenient protection.

Available in 6 different colors
Buy from Amazon or Garage Sales sellers.

4. Nexus 7 (2013) Premium Cover by Asus
Providing premium protection and proper views.

Available in black and white color.
Buy from Amazon or Garage Sales sellers.

and many more.

Here are example of few sellers in Garage Sales who are currently selling the casing for Nexus 7 (2013):
1. 88sales88
2. Dark Devon
3. tskhor
4. sakurazz
5. alf=red
etc.

1. Nexus 7 (2013) Sleeve by Google
Designed to protect your Nexus 7 while on the go, the form fitting neoprene sleeve features an asymmetrical zipper for quick and easy access. The sleeve is both padded and lined with microfiber fur for double the cushioning. A convenient outer pocket keeps all of your accessories close at hand. Compatible with all models of Nexus 7.

Available in Black/Grey.
Buy from US Google Play, not available in Malaysia set, but look out for Garage Sales section as forumers are bringing in from US directly.

Nexus 7 (2013) supports Slimport HDMI which connects your device to large screens and enjoy high definition full 1080p video with 3D graphics and audio, it charges the device at the same time too so you don't have to worry about the battery status.


Here is a short video showing what Slimport can do and how to setup:


Where to buy?
1. SlimPort® SP1002 from Amazon
2. kanex Slimport on their website
3. LYN forumer ybpow sales thread

1. Asus Dock for Nexus 7 (2013)
With its modern transparent hard shell design, this tailor-made dock for the Nexus 7 (2013) lets you charge the tablet while it sits up in an ideal position for use. The dock features a built-in HDMI port so you can view HD 1080p content on an HDTV or LCD display. It has a small footprint and features rubber feet for firm placement anywhere in the home or office. Whether in landscape or portrait orientation, the triangular dock design props the Nexus 7 (2013) to an ideal position for watching movies, playing games, or surfing the web, so you can still use the tablet even while it’s being charged.

Official Product link
Buy from Amazon

2. Asus PW100 Wireless Charging Stand for Nexus 7 (2013)
With ASUS PW100, charging your tablet is no more a nightmare of struggling with clutters of connectors and cables. All you need to do is just put your tablet on PW100 and then it will charge your tablet automatically. With embedded status LED design, you can also know whether your tablet is charging or is full charged. In the aspect of hardware design, PW100 is designed based on the new wireless charging technology. With Qi standard compatible, PW100 is compatible with most tablets or cellphones which also support Qi standard in the market.

Official Product link
Buy from Amazon

3. Nexus Wireless Charger for Nexus 7 (2013) by Google
No more messing with cords and plugs. With the Nexus Wireless Charger, your Nexus 7 (2013), Nexus 5, or Nexus 4 simply snaps into place on the magnetic face. Featuring a clean, compact design, the Nexus Wireless Charger adheres securely to a desk, nightstand, or countertop for grab-and-go charging.

Buy from US Google Play, not available in Malaysia set, but look out for Garage Sales section as forumers are bringing in from US directly.