>>>just how strict do you want to be with regard to the quality of the sites you link to?
There is no single answer for that. It has to be qualified by the site you are promoting, how long it's been around, and how long you want it to be around.
>>>EX: If a site has multiple links but they are 90% topic related and 10% totally unrelated would this still be considered valuable?
90% sounds reasonable.
>>>How about 80/20?
80% sounds reasonable.
Am I to be VERY picky when choosing sites?
You already asked this question and I answered it already.
>>>Or is there value in experimenting alittle with sites by adding a high quantity of links even if some are a little cheesier than others? (as long as they are not too cheesy!)
Either it's cheesy or it's not cheesy.
>>>Also, I am wondering is it logical for websites offering a product or service to agree to a recip link with us if our site will be listing their site along side multiple other sites offering the same service?
Isn't that what DMOZ does?
>>>But will they really want to link to us on a decent page on their site or will they be more likely to bury us on a bad page?
Most webmasters will want to bury you on the worst page they have. You don't have to do that, nor are you obliged to link to those people.
>>>Should this matter or is a link to a site that is offering the correct service valuable no matter what page your listed on?
It doesn't matter. As long as the page is getting spidered that's what counts. Check the backlinks of sites listed on those recip pages and if the site shows up then the light is green, move forward.