Agree with this too. If ur worried bout casing, chances are that ur not one to go for cheapo vanilla cases, right? Decent cases are usually pretty well designed for ventilation (except for some). If ur having problems with heat, then maybe u can manage ur wires a bit (with cable ties or tape for cheap fixes), add some fans (need some ventilation planning) and a better thermal solution for ur proc (heatsnk, fan, wcool, etc). That shouldnt pose a problem

On thermal performance, as usual, google for ur target case's reviews first before getting anything. If u already have a case and wanna make do with it, then ur choices other than an open case is thru modding, adding cooling components, and or rearranging ur stuff inside. Thats all i can think of anyway

So much for using those air-cleaner/purifier/ionizer gadgets too. I wonder if those have any effects on the pc. Likewise, cable management and a roomy case is a good combination, but against pet urine?