I don't have issues anymore with printing and networking. I understand that this stuff is per vendor so I usually do my research before buying (I have thinkpads, and my printers are all pretty friendly). I do see many windows computer fall over when printers connect to new wireless networks, though.
As for mp3, flash, isn't is as simple as enabling a non-free repository and let it do its thing? If you use Ubuntu the option to enable that is right at the installer. I've never had the issue since I switched to Linux full time (11.04)