Mintcoin is a 100% pure poof of stake coin now. The original distribution was several weeks by proof of work at first, for fair distribution. It is arguably the first coin of its kind, in the sense that it was the first coin to be released, with PoW at first distribution, with the intent to be later converted to PoS. Some other coins were cloned immediately after Mintcoin's release with an even faster initial distribution (basically instamined) in a few days, and thus technically became converted over to PoS first, before Mintcoin did. But Mintcoin was released first.

As for the syncing issues. I have never used the bootstrap before, just letting it sync block by block. If you do that it will take about a week of letting your client just run 24/7. Sometimes it seems to clock up, but if you jest be patient and come back in a few more hours, it will have moved forward and made progress again. The graphic user interface isn't always responding while doing a ton of syncing, but it IS still syncing in the background, u der the hood. Once it is caught up finally, you will be able to see it. Sometime restarting the client every few hours can help speed up the syncing too, IMO.

 Also it seems people with Windows 10 have been having more issues lately... Not sure, just saying, are u on windows 10?

PS, switch to Linux