as far as #2 goes, I would put it this way: I've had a pool for 3 years now, and every year I've had multiple algae outbreaks. sometimes it was my fault for letting the chlorine get to 0, but this year I was staying on top of my chlorine and pool in general because of my new baby (keeping he chlorine around 3-4ppm per the apparent pool industry standards). my leslie's swimming pool maintenance book they gave me when I moved here says that good circulation, filtration, brushing and chlorine is all you need to stay algae free. so when I had a big algae bloom this year (initially blaming it on pollen before it got so bad it obviously was algae) I was totally lost. I spent hours searching the internet and reading trying to figure out what the deal was. I investigated every alternative I could find (nature2, ozone, frog, etc.) more or less not caring about the cost to keep the pool nice for my family. but in all the literature, nothing ever really made sense to me of why it was better or why my way shouldn't work. unfortunately, on my internet searches virtually every link I found was poolforum.com which never worked. so I decided to follow pinch a penny's pool care plan to shock weekly, use chlorine tabs, and their all-in-one algaecide (whch was a polyquat 60 based algaecide). I would still be doing that today if the algaecide didn't cost $42/half gallon which made me search harder for a better solution. finally I found this site and the reason my constant chlorine levels didn't prevent an algae bloom - my CYA was too high for the amount of chlorine I was using (see chlorine/cya chart in pool school). thanks to pool school, I have a good handle on how to care for my pool and prevent algae from ever getting a foothold. if you ever fight algae (without the resources here) you will become a firm believer in the old saying "an ounce of prevention is worth a pound of cure." fighting algae is hard, expensive with the pool store chemicals and having to run your pump 24/7 plus clean it often, not fun and very time consuming. if you're looking to save time, daily testing and following the guides here is the way to do it.
also, you can still use a polyquat 60 algaecide (look at the ingredients for poly-really-long-name 60%) for insurance against an algae bloom if you want, it's just very expensive and you have to add it weekly.