Hi there.

I recommend reading the online How to Brew guide. You're missing a bit of information, and believe it or not I also made this mistake when I started out. http://www.howtobrew.com/

There is nothing wrong with your beer from what I can tell. Your hydrometer is reading 1.010 gravity because that's what the beer if FINISHING at. You already fermented your sugars into alcohol and that 1.010 represents how much sugar is left in the beer, likely unfermentable. 1.010 is normal.

Let's say you made your beer just about right and you're in the middle of the suggested OG on that data sheet you linked. 1.045.

That means you made wort with 1.045 gravity. Your yeast ate a bunch of it up and now you have 1.010. That means .035 gravity points were converted to alcohol during fermentation.

So then you go to the ABV calculator and you find that starting at 1.045 and ending at 1.010 leaves you with 4.7% ABV.

That 2% you're reading is 'Potential Alcohol' and doesn't mean much. If you had a cider, for example, that started at 1.010 and you fermented down to 1.000 you would have 2% ABV cider.

Straining your wort would do nothing except for adding oxygen which is a good thing for your yeast.

Tap water is fine.

Temperature is fine, 75F will not kill your yeast. If kept there for days, you may get some "off flavors", but that's it.

Good luck and when in doubt, Relax, Don't Worry; Enjoy A Homebrew :)