questions about connections and routers

[Cliff]

First I wish to compliment the programmers & maintainers of Deluge. The program & support is very good.
I'm running 0.5.7.1 on Gutsy and it works great!
I'm trying to learn how to get the most out of Deluge so I have a few questions, Which are:

1- I'm operating behind a public router/access point. Do the router connections need to be "kept alive"?
2- Is this done automatically by Deluge?
3- Is this governed by the maximum connection attempts per second?
4- Is this why my connections to Seeds/Peers sometimes go away and return even though there are hundreds of Seeds/Peers available?
5- What is a "half open connection"?
6- I am going to try PC Linux OS 2007. When I install Deluge on it should I be able to pick up where I left off using "add torrent" and browse to the file?

Thanks for any answers to these.
Cliff