Fuel filter replacement

[super_motarded]

Hi all - long time lurker first time poster. I really have 2 questions but primarily asking #2.

#1 - I have a high mileage '96 FZR with 45,000 miles on it. I bought it in January and have no idea what kind of maintenance was done on it. My main issue is that the bike starts & runs fine but it needs the choke lever pulled at least halfway or else the RPM's crash and it stalls out. I already replaced the oil and air filter, and ran two bottles of techron through 2 tanks of gas. Issue still persists. Anyone know what might be causing the need for the choke?

#2 - I bought this filter on amazon:

http://www.amazon.com/Show-Chrome-Acces ... lter+3%2F8

The OEM filter is 3/8 inches. I think it will fit. If not i'll make it fit. On my bike, someone broke the fuel petcock switch. The petcock is permanently stuck to "fuel on" and I can't turn it to off or reserve. When I change this fuel filter, am I going to have to have to pinch any part of the fuel line so that fuel isn't spraying everywhere or flowing out of my gas tank? Or are there any specific things to be concerned about? If so, what are they?

Thanks all