congratulations on your 17 r2.

about the battery, the answer is no, you don't need to remove the battery from the laptop, even if the laptop is connected to the adapter all the times (to me it's a good protection to power loss). since a few years ago, laptops already have a smart mechanism that prevents battery from recharging too frequently. when it's still above certain limit (i think it's about 90% or more) it will not charge. the charging only gets triggered when the battery is below that threshold.. furthermore, if you right-click on the power icon at the notification area, dell has a battery protection option that you can set up to help reducing recharging. it will cut off the power source, drain the battery, then to let it charge once in a while.

my m17x r4 is always connected to power adapter with battery installed. even after 3 years, my r4's battery wear level is still minimal.

however just bear in mind that battery is still wearable. it will wear more if you're on battery power most of the times.

which model is this? no issues with aw18.

Just set the speaker to the max and test it with one side of the speaker each time by playing some rock/hip hop music. I saw the old M15x got speaker blown up before. But that is the only one.

Sometime might not due to speaker, might have something is inside the speaker like bug that will create vibration with the speaker, but Alienware speaker design usually hv very small opening, is very likely the speaker is blown up. 

got update bios? check audio driver de?

try e_mc_square's method first, as it's physical, not software-related. if it had issues, call dell and wait for replacement.

until today my old m17x r4s' speakers are still good. (maybe because i never go above 40 on sound volume) i have 2 more spare speakers in case they break down.

Don't felt sad bro. You still covered by warranty 

afaik, no, it's not common. my aw18 r1 has just been upgraded to w10 fall update (build 10586.3) via windows updates without glitches.

if the weird stuff persists, you can revert to the previous one. alternatively, maybe a system/factory reset could help also (a clean install is even better). i know this seems like a lazy answer. however i have done that to all my machines (clean installs) before i use them, and i never had any funny problems before.

since w7, it's better to create system images from time to time. in cases like yours, a system restore will save you a lot of time to crack your head trying to figure out the causes to your issues.

Able to recover?

don't mention it.

if it's about replacing the ac power adapter to a 240w, then it's much easier. besides the official replacement from dell that i think it will take time to resolve, you can get it online.

from the information posted in dell website for 240w adapter:

http://accessories.us.dell.com/sna/product...7&mfgpid=242558
http://accessories.us.dell.com/sna/product...3&mfgpid=242558

the manufacturer part number for the 240w is 6RTJT. when you check adapter models that it replaces (the second link), you will see FWCRC / 6RTJT / J211H / Y044M / 330-4128 / 330-4342 / 330-7843 / 331-3179. in short if you get any one of the adapters, it will work for your laptop.

you can get one from dell directly, or, here are what i found at lelong:
http://www.lelong.com.my/dell-pa-9e-240-wa...7-01-Sale-I.htm
http://www.lelong.com.my/brand-dell-alienw...7-01-Sale-I.htm

you can also do some leg work yourself to find out options at other places.

good luck.

cheap at Taobao.com, expensive at dell service center.

Sysnapse Malaysia at Georgetown. Original parts but is cheaper by alot.