Hi, I think mill is definitely a playable deck (I've played it a lot when it was in ravnica standard and then in modern).
I find that just mill, or mill and creatures is actually a weak strategy due to the fact that you don't interact much with the opponents board. for example, if you cast a mill spell or hit with mirko every turn unblocked (assuming he doesn't die to removal) Then you still only affect what your opponent would have drawn. So he could still draw lots of big spells and kill you even if you mill away most of his library. I think you also want to play more lands. generally, 22 lands is reserved for aggro decks (like mono red or affinity), which play between 17-22 lands because their cards are cheap and they can finish a game with just 2-3 lands.
for a deck like yours which has cards which cost more than 3 (even 5 and 6 You want to be playing at least 24 lands. Yes, at least. A better number would be 25, because if you have no mana you can't play your better spells. you could probably get away with 23-24 if you had more card draw because only
staff of nin won't help that much. especially if you never have enough mana to cast them.
If you go the control mill route you would be playing 26-27 lands, and have a metric ton more card draw, because that's what control would need. but with a lot of mana cards like
sands of delirium become much better.
Here is the list I played a while back, I haven't updated it in a while and would probably change a lot up if I had to build and
tinker with it again but it should still give you a good idea of where to start with a control type mill deck =. for mill-gro, max out of
jace's phantasm and the
mind funeral, some black removal maybe and lots of cheap creatures like
wight of precinct six. a good mill-gro strategy is also
invisible stalker and other hexproof or unblockable creatures equipped with
trepanation blade.
If you want to discuss more of have more questions feel free to ask, I'm sure there's lots more to mention about milling as a strategy.
Happy Milling!
The best way to win via milling is not to think of it as your primary strategy , or even the most important. To me there are two ways of doing this, either playing mill aggro or playing control with a small part on milling.
mill aggro (or mill-gro) is when you rely on combat damage to win, but milling fuels this. cards like
jace's phantasm and
wight of precinct six become your early creatures which can get really big, while cards like mirko, lazav and even consuming abberation become very powerful creatures. milling is a good theme for this deck, but ultimately it relies on combat to win. a deck like this has a hard time against control which can counter your mill and kill your creatures though. it also has a hard time against combo decks and decks that can simply go bigger in terms of creatures.
Control makes the best type of deck to play mill with. When you play control mill, you essentially play control with mill being a slow and grindy way to win rather than a fast and big one. you would generally play lots of ways to draw cards, as well as counter spells and kill spells, and only play a few mill spells, but your mill spells would be cards that you can use over and over e.g.
jace memory adept and
millstone.
I found that the control way worked more for me, but I also played mill-gro when it was in standard in innistrad/return to ravnica.