As stated already, you should be fine with a low pitching temp... Better to pitch too cold than too hot as far as I'm concerned. Too hot can kill the yeast, too cold will likely just slow down the process of them coming out of their dormant state. You shouldn't really have any adverse side effects from this other than fermentation taking a bit longer to start up but once it does all should be well.
As for your OG being off (though your so close you shouldn't be concerned) can be caused by a few simple things (none of them that you need to be worried about at all, but if you're like me, you want to know why things are happening the way that they are):
1.) Extract often varies slightly from manufacturer to manufacturer and sometimes batch to batch with regards to their % of fermentables.... this can lead to a slight variance in gravity.
2.) I'm assuming that you probably used top off water to achieve your final wort volume in your fermenter. When doing this its often tough to get accurate OG readings because its very difficult to completely mix the top of water and the wort together. Because of this, when you draw a sample for OG you can easily get an overly concentrated wort sample (resulting in a higher than expected reading) or a overly diluted sample (resulting in a lower than expected reading). Its absolutely nothing to be concerned with, its just something that you have to deal with when brewing partial boil extract batches.
3.) Did you remember to adjust your reading for the temperature of your wort? Most hydrometers are calibrated to read at 60 degrees.
As for inconsistencies with yeast packs that come in brewing kits, You're absolutely right. Its tough to determine how old those yeast packets are and impossible to know what sort of conditions they were stored/transported in. Its definitely a good idea to buy yourself a quality yeast (liquid or dry) and dispose of the ones you get with your kits.
Finally, Welcome to HBT and to Brewing!
Cheers!
