I think all most of your questions are answered in this recipe:
http://www.poolforum.com/pf2/showthread.php?17055

But, I'll make some other remarks:

1. Until you get a good test kit, you are -- as it were -- driving with a blacked out windshield, and will only discover that you were going in the wrong direction, when you hear the crunching sound, and feel the impact. Nothing we can do here, can make up for the lack of adequate testing.

2. Chlorine does not cause allergic reactions (ever). Chlorine does not irritate people (usually), even at high levels. BUT, chlorinating inconsistently or intermittently results in the production of some very irritating chlorine compounds. The solution is not LESS chlorine; it's more CONSISTENT chlorination! However, you won't be able to do this, till you have a good test kit. (Notice a theme, here?)

3. The whole "must let chlorine go down to swim" is based on a series of historical accidents and institutional inertia, not on science or health. Dermatologists have for years -- and still do -- treat both adult and pediatric patients with "bleach baths", which involve bathing in 50 - 100 ppm of chlorine for 30 minutes or so. Relatively high levels of chlorine are NOT a problem for people; they may be more irritating to eyes, but I'm not even sure of that. But, they can be damaging to women's fashion swimwear, depending on the stabilizer level. (Of course, to know what the stabilizer level is, you have to have a good test kit!)

4. The major pool chemical companies -- Arch/HTH and Biolab/BioGuard/Chemtura -- have increasingly engaged in behavior I consider predatory, and are selling chlorine blends that I consider to be very undesirable. These blends include compounds that are essentially useless (magnesium sulfate) or not appropriate for general application (aluminum sulfate), or likely to cause problems (various copper and persulfate compounds). In particular, Chemtura -- who is in bankruptcy (www.chemturacommittee.info) -- seems to me to be acting in its own short-term financial interests, in ways that are directly contrary to pool owner's interests. Between them, these two companies control most of the brands available to homeowners, via both retail big boxes like Walmart, and via pool stores. As a result, pool owner's need to be extremely careful about what they purchase, and should avoid 'blended' chlorine products like the plague!