Perspex (Acrylic) is less bendy in its normal state than lexan (polycarb), but easier to bend with heat. Lexan is possible - I've done a sidecar screen (sorry, for this forum, errrm, record player lid
) in 2 or 3mm lexan, and put two 50mm radius bends in it with two heat guns and a lot of careful bending round a former. It took ages, and was really tricky - too hot locally and it bubbles. In a factory they do it with a huge humid oven over a former, and apparently it just 'flops on' when you get it to the right temperature all over.
I've made tanks for water and sand at work in lexan, tapping threads just into the plastic itself. I think I used 24mm sheet, with M8 threads, and something thinner with M6. It works OK, so long as you do not over-tighten and strip it. We have some kind of super-runny glue too, but the joints have to be _perfect_ as it has no gap-filling properties at all.
It's quite nice to work with, on a big table saw with a sharp blade, but less forgiving than wood.
Another thought - I've made stuff which just slots together, no fasteners at all - a bit like '70s scandi-cool furniture from Habitat.