won't destroy, that's why need to LIGHTLY sand it..
use gloss...
flat is flat because of the particles
semi gloss still have a little particles therefore in the middle
where as gloss has not particles which is very smooth and best for applying decals...

Don't worry about multiple coats as long they are not THICK coats..

a thin layer to make it smooth for your decals so when you apply you decals, it'll blend nicely(of course with the help of mark setter or mark softener)
last layer of coat is up to you which is semi gloss... It won't affect your decals, dont worry.. If you're using spray cans for top coat, just be extra careful of frosting...

What we usually do is, sand-->prime-->paint-->gloss(optional)-->panel lines/decal-->final coat(coat of your choice)

sure, i'm glad if i'm able to help...

Alright, 1200 surfacer/primer is the smoothest so it should be alright. Your result for not being smooth might be the contents inside are not "mix" well enough or spray too thick.. Airbrush won't have this type of trouble
Yes, if you do not have a proper ventilation, dust will be everywhere..

you want very gloss, then you need to polish using compound and like how people do model car kits, a lot of steps...
using spray can difficult to achieve as its paint is not smooth. Spray can(industrial ones) gives rough surfaces...

No, normal car polish is for REAL CARS. lol... it's more expensive than hobby one la..
I am not good at doing glossy like car kits, i just roughly know the steps...

After painting, you need to wet sand(sandpaper or sanding sponge dip in water) and slowly smoothen the surface(using 2000 grit and above) then gloss coat - > compound.. etc etc for EVERY SINGLE part if you want the whole kit glossy. Cars usually just the body so easier than doing gundam kit parts by parts

If you love this hobby and want to achieve nicer paint job with more control and will yourself painting often...
then what's stopping you? i dont see you have a budget problem

yes and also i feel that you are capable as well.
The first MG i painted, i bought mr.hobby spray cans. The amount of money i used is more expensive than the kit already, and i was like wtf....

You definitely need an spray booth(with exhaust fan) if spraying indoor.. The fumes are actually poisonness if you smell too much, it ain't good for your health.

it actually depends what kind of finishing or paint job you want, if simple paint job, i would say fast la. Of course can't compare to spray can. Do note every time you finish AB-ing, you'll have to clean the hand piece which may take 5 mins to do.
Seriously, you love this hobby, just invest in it. You'll see all kinds of finishing you can do with more control. You won't regret getting the AB set

it's best not to spray on a rainy day...

yes, like what nazrul90 said, dip it in a warm water for like 5mins and shake well before spraying it.

definitely gravity-fed if you mean the cup is on top...
most of us use that...

yeap.. just get 0.2 or 0.3 for normal use.. the smaller the finer spray you control usually like camo..
0.5 can also but for normal spraying if spray normal colors.. can spray faster and cover more area due to bigger hole..
most of us use 0.3.

If you using industrial spray can then it's difficult as their paint is already thick.
IF it's hobby spray can, then you shouldn't have a problem of spraying smooth, just keep a distance of 30cm or so and spray left right.

no cons as long you don't mess up..
reason why we separate parts because of the color and we can spray them properly.

when asking this question is kinda pointless, in the end it's up to you. 3 ppl can recommend different color schemes and you may either choose one of them or none. Just go look around other works and get inspired and come up with your own color scheme.. This question is just too subjective.

good, you already have an idea so go ahead with it...
It should look on the theme if you able execute it..

As for a beginner, i always always recommend ppl to start with an OOB kit. Just do an OOB kit to get the fundamentals right before even going into other stages. That you won't screw up easily..

Did you even primed/surfacer it?
If no, that's why..

you're suppose to prime/surfacer --> base coat --> topcoat(gloss for enamel) --> enamel --> topcoat

That is why your paint didn't stick well..
and why you go gosok your paint. lol

no worries.
for best results, let the paints/prime dry at least 1 day before you start another layer or you can take the risk.

transform kit, if you "play" it.. paint sure scratch one.

When i started gunpla painting, i used pylox. it's suitable for gunpla but beware not to spray too thick. Spray at least 30cm away. Spraying directions left right left right(hope you get what i mean). The finishing is good if not painted too thick.

Bro, go invest a cutter, get a RM50 cutter from tamiya would be sufficient, using it right now. can cut sharply and the quality is great.
You can go for the RM100 cutter from tamiya if you have the moolah.. lol...
Cutters are the most used tool in gunpla so spending abit more for it, it's definitely worth it.

htpkevin, Are you staying at PJ?
You should check out ICW@Aman Suria for AB guidance and get hands on there..

Nope, it is not gloss coat.
It is achieved by using air brush using the right paints.
some paints give metalic/metal feel like Gaia series

RM100+ can get a Airbrush hand piece(the gun) but china brand type.
If you're in PJ then you can go to ICW to use their compressor(For free). A decent compressor would cost at least RM400...
To achieve metalic/metal feel, using air brush is the way to go because hand paint is unable to achieve the smoothness of the paint.
Although spray can have them but they might hurt your plastic OR over spray resulting thick layers

would not recommend this. You will still miss certain parts of the are that you need to spray.
Satay sticks are the way to go. Satay sticks aren't expensive. Get aligator clips or use blu-tac with them to hold your gundam parts.