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
Yes MintCoin was more than just a copy past coin when it was launched and was innovative with a short POW period leading to POS only.
I calculated that from taking the average of a few hours of syncing that it would have taken me about 6 days to sync fully at the rate of sync I was getting, it was too long because I was due to stake and missed the wallet up date so I had staked with a dud wallet previously I didn't want to loose out by going over the deadline of 11 days as it was then. Syncing does work yes, it is just very slow when compared to some other wallets but the number one coin BTC is a terrible wallet to sync in my experience and I was trying to sync that up as well.
The bootstrap was easy once I realized that I only needed the contents of the zip file and was forced to install 7zip to unzip the files.
As for Windows10 I wouldn't touch it with somebody else's equipment, windows stopped at 7 for me and I am moving to Linux slowly.