DPoS is actually less centralized than a lot of other coins if you actually look at it. Also, you can now deposit and withdraw fiat with OpenLedger. Or at least you could do it a couple months ago if it wasn't removed recently.
I've yet to find a better DEX than BTS.
have you tried CryptoBridge?
I did awhile ago when they first launched why? It's pretty similar to OLedger right? Unless something has changed?