Flat clear coat as primer?

I've heard some say that a can of flat coat can double as primer to give the surface of a fig "tooth" to adhere to.
Now I'm heading to the Tamiya's proprietary specialist shop tomorrow, and as a relative beginner to serious modeling and customizing, I've already got a crapload of stuff to buy. If I can help it, I'd like to save some money by having the flat coat double as a primer, instead of buying a dedicated can of primer. Or would that be foolhardy, if in the long run, primer is actually cheaper than flat coat [don't know the price of either one yet]?
In any case, is it actually A MUST to prime the parts of a fig before hand-brushing and/or spray painting? Can Pledge Floor Finish for Tiles and Vinyl f.k.a. Future floor polish double as primer?
I've also heard of Tamiya Wax. Does is work on unpainted figs, if I just wanted to give a TF's alt mode a glossy shine and protect it from scratches [like ROTF deluxe Sideswipe's silver paintjob]?
This is going to sound like a stupid question, but do I need a mask even when spray painting outdoors?
Thanks in advance.
Now I'm heading to the Tamiya's proprietary specialist shop tomorrow, and as a relative beginner to serious modeling and customizing, I've already got a crapload of stuff to buy. If I can help it, I'd like to save some money by having the flat coat double as a primer, instead of buying a dedicated can of primer. Or would that be foolhardy, if in the long run, primer is actually cheaper than flat coat [don't know the price of either one yet]?
In any case, is it actually A MUST to prime the parts of a fig before hand-brushing and/or spray painting? Can Pledge Floor Finish for Tiles and Vinyl f.k.a. Future floor polish double as primer?
I've also heard of Tamiya Wax. Does is work on unpainted figs, if I just wanted to give a TF's alt mode a glossy shine and protect it from scratches [like ROTF deluxe Sideswipe's silver paintjob]?
This is going to sound like a stupid question, but do I need a mask even when spray painting outdoors?
Thanks in advance.