I’m with Liam; I load the next map very fast.
Loading the next map is very hard drive intensive, hence why laptops suffer.
The easy solution is to buy a faster hard drive and more RAM. Since you mention the game crashing when you press the start button, I’d guess you have enough RAM for TF2 and nothing else. If you post some more detailed specs, we could advise as to an upgrade or tweaks.
Sprays are the most unpredictable thing. .jpgs work in theory, however .bmp seems to be work much better. To convert to .bmp open your intended image in MS Paint and hit File->save as then choose bmp from the filetype. A quick google search has turned up this tutorial on FPSbanana, TF2 Spray Tutorial. I haven’t done that in a while but I recall it works with a minimum of screwing around.
I hope that helps.