Congrats on your new tool!  I also have one and I admit that this is one single tool which will be very useful for you for years.

There is a minor problem, its not easy to get the replacement blade for this model. I have tried to search around without success, except perhaps online which I haven't tried purchasing physically yet.

It is not cause by the put the chuck max.

For drilling big hole, start with a small drill to drill a pilot hole 1st. Gradually increase the size and than finally the hole size you want.

Buy the one with advance Kick Back control, although bit more expensive but worthy of safety.

you're gonna be dissapointed.
180nm is pretty weak to undo tyre nuts.
especially if they tighten using those pneumatic impacts. those are rated upwards 500-600nm

my gds250, rated at 250nm won't undo them.

Yes it supports both, but bear in mind it's a medium powered cordless impact drill, don't expect it will drill through brick walls like butter.
You can hammer nail directly, but it will be weak, so people usually do this only to hang very light items like clock or small photo frame. Go for wall plugs if you want stronger support.

You can buy OK brand like Black Decker, Stanley, Bosch with Rm 300 budget, maybe you can get better deals at 11.11. Make sure you know which kind of drill you want i.e. impact/hammer/rotary hammer drill

So which is OK brand and which is atas brand? Haha

If I were to get Bosch, which model is recommended for simple drilling into walls to insert screws/hooks? Not really getting the difference between the GSB and GBM range. And what's the difference between a GSB 10 RE and a GSB 500 RE? Bosch website doesn't have anymore info on the 500 RE but there is a hardware store near my place selling it.

go buy Bosch GSB 120-LI

impact drill with li-on battery

price also similar   

wah so big nails. i am using 18ga cordless.

I do have cordless 16GA and 18GA nailer by ryobi, last time itchy hand bought used/refurbished unit from taobao.
The 18GA tends to hit too hard and leave a hole on softwood like pine. 

Now I am thinking of getting the ryobi U nailer to complete a set.
U nailer should be easier to nail aluminum heat shield foil on the roof...

yea.. ryobi. works out well when u dont want to lug a compressor to site for just 10 shots.

10 shots feel like home DIY.
Small repair to the roof.