I can't really answer that
It's luck whether a new host with your files comes on line and shows with your current connections, as it is if you get better results by changing your connections. Personally I seldom remove the connections, but once in a while I do.
Yes having a new set of hosts may well affect your chances of finding a file.
You have a good speed and obviosly look for rarer files. It might be worth the small amount to invest in Limewire pro which gives you 5 host connections (I think ..memory is going lol
I hope this helps