Long time ago I’ve installed Win7 32bit on friends Satellite L300. It worked perfectly. Much better than original Vista.
I'm still not sure what is the best test for the screen.
I don’t understand what kind of test do you mean. I hope you have installed right display driver and LCD works perfectly with native resolution.
Creation of Win7 recovery image with Acronis is, generally speaking, good decision. With this disc you can install Win7 again and again very quickly and you must not install every single driver separately.
If you want to keep this notebook for longer time I think it is worth to buy it. One more thing: you will buy it one time and you can use it in the future too if you will decide to buy new notebook or PC.