Precautions before installing custom ROMs?

Hi guys, I am new to this Forum.. I wanted to root my GT-N7000. So i searched the forums and i followed the guide of Dr.ketan and used the recommended method ( 1A - Flashing safe kernal with CWM recovery with touch 5 ). Had a bootloop on second restart, ( did reset and rooted the phone using the 1B method flashing SuperSU and Busybox ) Nevertheless successfully rooted my phone. :D

Now i wanna try Custom ROMs..Is there any precautions to be considered other than Nandroid backup?.. Also i have only a 2GB memory card.. Would it be enough to make Nandroid Backup?..

I also read by Installing Custom ROMs, we will lose Stock apps ( Since apps like S Note need some TW kernal ).. Is there anyway to Port or install or Mod available to install stock apps like SNote and Splanner in Custom ROMs?..

Finally, will the SPen work with Custom ROMs??.. I mean will the Custom ROMs for Note will have the Kernals Inbuilt for SPen or we have to install the Kernals required?..

Thanks a lot for viewing this thread and Thanks in Advance for your replies :o



PS:- Please excuse me, if the above questions have been asked before, cuz i searched for it and couldn't find it or they were complicated for a noob like me! :D