Yes. When you relaunch it, be sure that you do not have --reindex or --reindex-chainstate in your command as those will cause it to restart the reindex. When you start it again without those options, it will pick up where it left off.
Well thanks for that, I knew that I did the right thing.. I was about to close my computer and run it again later, I just wanted to hive my poor laptop some breathing, it has been working 4 days in a row now and it's summer, im still at 70%...
Unfortunately you can't. Older versions of Bitcoin Core do not know what to do with the HD wallets, so they will refuse to start with one.
On that case, I guess I can always download pre-0.13.0 Bitcoin Core and generate a new wallet.dat file there to still stay with the old wallet format.
I just don't see any positives going into a format that's not backwards compatible. HD wallet doesn't seem that important, it's not like you can save a seed and generate the wallet like you do with Electrum, so I don't see it as being a "must have". You need to keep making backups everytime you create new addresses, but that forces you keep making said backups and stay alert and keep an eye on your wallet files.
