Is it possible to replace SMC and keyboard

Sounds like you're between a rock and a hard place here ;-{

So for starters you'll need to replace the complete upper case assembly (keyboard & trackpad included).

As for the logic board the chip is soldered to it and not easily replaced, Thats not to say it can't its just beyond most DIY folks (I don't even do it any more as you need keen eye sight). That then leaves you with the expense of replacing the logic board.

Between both costs and the labor it might be cheaper just to get a new system (used). Are you sure the chip is damaged and the logic board only needs be be cleaned to be it back working?

You might still be able to recover what you have on your systems SSD by buying this: OWC Envoy Pro Portable, Bus-Powered USB 3.0 Enclosure For Apple Flash SSDs (June 2013-Current Mac Models). Give them a call to double check.