Are you meant to bring the bar all the way down to your chest on this excerise.

Also will doing 3 excerises before getting onto bench press affect my performance?? At home I usually do it first and do sets of 10 9 and 8. I was actually hoping no slightly increase weight in gym but I couldn't get on for awhile and when I did get on I could only do same weight but 8 6 5 :-(