AG questions from a newb

Hey all i had a couple quick questions about going AG, my first:

Is it safe to use these plastic 5 gal circular coolers as containers for HOT liquid? I am in the middle of constructing a MLT with a LOWES/rubbermaid blue 5 gal beverage tank and I am concerned I may pull out some carcinogens from the plastic or some wierd thing like that if the plastic is heated.

My second question is: Would the northern brewer AG oatmeal stout kit be a good choice for my first AG? Anyone try that one? It is low in the grain bill department, and it is dark so would that be a bit more forgiving if I dont hit my temps (high or low) or make other newb mistakes? It is 1.042 OG but if I added 2-3 more LB of base malt and maybe .5 oz more bittering hops, would this be a fair adjustment to bring it up to around 1.048 - 1.058 and still taste right?

One more Question, how worried should I be about pH if the water I use is Poland Spring from 1 gallon jugs? Is this pH business entirely based upon the water you use?

Thanks a lot for everyones help, hopefully I will be mashing in by next friday morning!

Well, since a substantial percentage of us AG'ers use picnic coolers... either there's no problem, or we're all ****ed.

Can't speak to that particular recipe, but I'd be inclined to do it as-is. I imagine they're formulated at a moderate efficicency assumption, and if you miss it REAL bad, it would be easy to adjust with a bit of DME after the fact.

pH is more determined by the mash than the water (unless the water's real messed up). Buy some 5.2pH Buffer (a tub will last a long time), it works like an absolute charm to keep your mash in the sweet spot. Don't stress about pH.

thanks man!