1) isit ok to leave ur com running the whole day?
1) Yep. FYI I am using a laptop, which consumes low power for
low bills 
2) at what temp should we shut down the computer
2) I've seen my CPU reach 60+ degrees without any problems. Use
a fan if you want to keep it on 24/7
3)com hot, related to com being laggy?
3) If comp too hot it may auto trottle = laggy, but usually its
becoz of other factors
4) even if canot keep it running for a day, what is the longest
time?
, considering that it is a average com
4) My record is keeping my laptop on for 2 months
5) what temp inside the CPU is ok? veri high? average?
low?
5) 35 when you just start the comp, 50 is the norm,
imo