1. If you don't want to use muriatic acid, you can use dry acid (PH Down).

2. I have never used PH Down so can't comment on amounts.

3. Any pH reading between 7.2-7.8 is ok.

4. Since you have no CYA and you are cleaning up a swamp, I'd aim for a shock level of around 10-12ppm. (If you haven't yet done so, read the Best Guess Chlorine Chart in my signature below.)

5. You can do it either way. Doesn't really matter. Using dichlor is an easy way to add chlorine and CYA but either way works.

6. You may need to refill the R-0870 and R-0871 and likely the CYA testing reagent. Actually, the K-2006C is a better buy --- 2 oz. bottles instead of 3/4 oz. bottles. Once you get the pool cleaned up, you may want to just use a cheap OTO/Phenol Red kit (yellow and red drops) for daily testing and use the good kit periodically. That is what I do.)

7. Is your trip soon? Or will you have time to clean the swamp first? You can certainly use some polyquat. But, don't use any other type of algaecide.

8. Depends on how long you are going to be gone. Get your pool cleaned up, take your chlorine up to shock level. Maybe have a neighbor come in every few days and add some bleach.

Hope this helps.