I didnt like the fact that the seat didnt lie completley flat, the seat part was always at a 90deg angle to the seat back. Also when DD sat in it, the seat part is too hard and she ended up slouching as she slipped forward. Most strollers have a soft seat not a hard board to sit on. It is also mega wide, and a pain to fold up, and is huge when it is folded. Also the most upright position is not as upright as other strollers, it is quite laid back and also made DD slouch.
I much prefer my Milano stroller, its a good solid thing, folds easily and works for DD, the only thing is its not rear facing, but I brought the other steelcraft stroller that has 4 wheels and a reversable handle, its a bit of a pain to steer but I muchly prefer it.
Hmmmm the clips sound s bit strange, i remember when i put it together it looked like it wouldnt work but i tried it and it clipped in properly. I dont see how the front wheel doesnt fit, it should just slot straight in. have you taken the protective cover off it (black or white tube thing)? Otherwise try turning it the other way???
If you really decide its to much of a hassle take it back and get something else, there are ones that are much cheaper that work better IMO. Good luck and let us know how you get on