No, it is a mono amp and you will need a higher watt amp as well as more channels to power those speakers, otherwise youll notice cutout when maxing out volume. Get a 2 or 4 channel amp.
That is dependent on the wattage of the subs this Amp will push 150w RMS 2 channel at 4-OHM, or 300w RMS 2 channel at 2-OHM with no problem but that will be pushing the limit of what you can do with this amp.
You could but I wouldn't. You would have to turn the amp down. Or your taking a chance with blowing the sub. The amp is rated at 600w RMS at 2 ohms. While the 12" kicker CompR is rated at 500w RMS at 2 ohms. I have this amp with a single 12" kicker solo basic L7. At 2 ohms it's rated at 750w RMS. It cost a lil more but my sounds good.
Yes it will power both 15's but I would get 2 of these amps and run 1amp to each 15. That way your not gonna have any overheating issues or issues with what ohm your speakers are. If you have a 1 dual voice coil 4ohm subwoofer it equals 2ohm. If you have 2 4 ohm dual voice coil subs that equals 1 ohm to the amp and Thats series or series parallel with dual 4 ohm subs wired one way or the other = 1ohm or 8ohm and so if the amp isn't 1 ohm stable your gonna blow the amp or overheat it go to kickers website for wiring diagram of speakers but 1 amp per sub you won't have to worry about what ohm your dropping to unless you want the max wattage output from the amp