Originally Posted by PhalzyrD

So wasting countless gems on bad chance to get a decent girl on premium pull isn't silly, but using one gem to give me enough stamina to continue playing (and possibly get 4+ gems to replace it) is silly? I guess I could wait five hours to level before playing and thus use them more efficiently, that is true but silly? Maybe not as efficient...

Using gems to get a stamina refill is almost always silly, honestly.
It "just" speed up things a little bit, giving you more gold/manyuus/seeds/gifts... which can be farm every day, while using gems is the only way to get 5* (and 6*, but eh).
Obviously, you'll sometimes get bad draws, but you can't really say that rates are bad...

Originally Posted by PhalzyrD

However in some cases I have actually gotten gems I wouldn't have that day if I hadn't rejeuved stamina...

Except if it's for a time-limited quest, there is no need to rush (and to use gems to get a refill), as you can always try again later.

Originally Posted by PhalzyrD

I should probably save some manyus for Lavender... 23/24 medals, think I'll leave it at that...

Why are you stopping at 23 medals ?
I mean, why are you saying "no" to 2 free gems + a power-up on Lavander ?
Unless you're not powerful enough, of course, yeah.