If you've a bit of experience with cellulose resprays and can live with the elbow grease needed, I'd stick with that. Some of the modern formulations are more durable and more forgiving than the older celluloses anyway. On this type of respray I must re-iterate the sense of coating the car with barrier coat it'll only add about £20 and about 2 hours work and could save you days and days of misery and a horrible 'crackle' finish car.
I take Lagdti's point about abrading plastic panels with coarser grits - but if you are flatting rather than stripping ( and you can't use paint stripper on plastic cars - melt them - yes !
), then it shouldn't be a problem. My comments are based on just how long I perceive it would take you to flat a rough finish with 1200 grit .......ages.
Having said this........are the plastic trim panels painted or self-coloured plastic? ( I'm not sure on this car). If the latter, then I agree, there is a risk of scuffing the plastic with coarser papers and I'd move up to 600 grit on the plastic. Try it on one of the less obvious areas first to see how it takes it.
If you've no experience with 2-pack and haven't got reasonable facilities for proper ventilation then stay away from it. Belting iso-cyanate around and wafting it over the neighbour's fence is both dangerous and anti-social - and could get you 'nicked' if someone complained.
Having said this, I think the risks of isocyanates are often over-stated - the odd panel in a well ventilated room with a good face mask is probably not going to do you any long term harm. Do it regularly and haphazardly and it'll probably 'get' you after a while. Isocyanate is not the same as 'cyanide' (there are chemically similar molecules there though) but it is toxic and will absorb through the skin as well as the breathing risks. In the long term, exposure causes problems with internal organs........but then again, so will cellulose thinners!
Get you're pics up and lets see what you're up against