emmc is a nice speed increase and one of the main reasons for choosing a SBC over an Android box.
You can use your existing remote if you can find a configuration file for it, otherwise you can create one yourself just so long as you can work out the code standard, the process is well documented and there is a good database as well. CEC is nice as a backup but on mine it hasn't got the context menu mapped which makes a lot of operations painfully limited.
I find that the on screen keyboard is adequate for all my needs - if been a little painful to use. I wouldn't bother with a remote keyboard, just wouldn't use it enough to make it worthwhile.
2g of memory is fine and always will be for Kodi/LE. The only reason to go for 4g is if you intend to run ubuntu or Armbien.
The VIM3L will be a huge step up from your current box and you will probably see only marginal benefit going for an N2 over it. Still the pricing is close so i would still go for the N2.