Dogecoin core developer!
https://www.reddit.com/user/rnicollRBF is awkward in as much as I don't like it, but I have to accept that it makes economic sense (and miners will patch their clients if we don't enable it). The main drawback to RBF is it makes zero confirmation transactions even less safe, but with 1 minute block times I'd rather we discourage zero-conf transactions anyway. No firm plans, I don't want to make it default, but there's no point in us keeping it opt-in then discovering all the miners are modding their clients.
0 fee transactions - I'm not planning on changes to the fee costs, but also am not quite sure what went into 1.10 without checking the code. I know we had problems with transaction spam and I'm trying to remember if this was sacrificed to fix that :-/
SegWit may be in 1.15, mostly for the transaction malleability fixes, but also so we maintain compatibility with Bitcoin/Litecoin for anyone building services on them.
Compact blocks - yup. I need to make a pre-release checklist, so I can add testing them to the list, but absolutely would expect to see this in 1.14.
RPC - I'd be crushed in getinfo goes because I use it day to day myself, as a nice summary of state. getrawtransaction I think is being changed for performance reasons, though, so that is likely to follow Bitcoin Core. However they've said if you maintain a transaction index, it'll still work as currently, so that should be fine? Fee estimation is fairly new, so I'd presume anyone using that is still maintaining their code. Any I've missed?
Many thanks for the tip!
P.S. The main issue with SegWit is the default mechanism for enabling it breaks AuxPoW. So there's some questions to resolve there, first, basically.