newbie setting up a 28g nano cube

[aness2323]

Just bought and set up a 28 nano cube. So far I have added live sand, 30 lbs of LR, set up the filter with sponge, carbon/purigen, and ceramic discs. And added LFS sw. I added a heater to the heater space next to the filter tray, and a shrimp to start the cycle. I have had trouble heating the tank. Someone suggested staying at 78 deg. With the lights on I am around 77, and with the lights off, I am running around 73. I may need a better heater at this point. Besides heater questions, I am interested in setting up an ATO, and later a fuge and light. I would like to add a protein skimmer, but am not sure which could work with the filter container in, as well. Is a light upgrade needed, and can you add MH lights, and still have the same hood. Lastly, someone please explain for newbies about the power head vs. pump, and which would need upgraded for increased flow. I understand a new power head would increase flow, but do you need a new pump, and why do some people remove the stock pump and add it to the first chamber. I know its alot of questions, thanks