I have a few mages myself and wasn't really hit too hard by the spirit changes...mostly because spirit was awful for us for so long (outside of arcane specs, but arcane didn't stand on its own legs for quite some time).
Wall o' text incoming
I've almost exclusively done my level grinds as frost, but lately have been playing more with fire specs on my lower levels for a few reasons. I do have downtime, but it's not significantly longer than it was before. Obviously frost had less, but that wasn't unexpected. I've also tended towards skipping instances along the way through my levels. They're fun, but I already have too many alts at cap level (and two accounts, so I can run myself through them if I really cared to) and the levels fly by these days anyway even without them. My common joke is that I sneeze and gain a level now
On to your suggestions...
I like the idea for mana gems. I've always found it a bit silly that lower-level mana gems never received the "charge treatment" that cap-level gems got. With the potion changes, I would think that adding charges to all mana gems would actually give lower level mages a bit more to work with and allow them to get into the same habits for mana management that they'll need at 80.
As for conjured water, I somewhat agree with your suggestion, but have some reservations. I've never seen the problem with having conjured water/snacks outscaling vendor-provided refreshments. Other classes already have discrepencies between vendor and player-made items, so why should food/water be any different? Examples abound, but the most common has always been ammunition (pre-BC, best was from Scale of the Sands, with engineering ammo falling behind even other factions' ammo; in Wrath, engineer-produced ammo is significantly better than vendor-bought). Back to the topic, though, mana and health pools quickly outpace what any food/water can replenish, and yet we still have refreshments that do not scale in any way. My DK has over 30k health and my undergeared holy paladin has 20k mana...neither of which can be filled by a single strudel, and it's just going to get worse (I'm not far from needing two complete strudels for my DK). Many people have suggested percentage snacks, but I'm more inclined to just say "buff conjured snacks altogether" instead of going to a fixed percentage. I don't mind eating more than once, but when I can foresee reaching two full eating sessions, it screams "increase their effectiveness by 25%" at the very least.
I absolutely cannot agree with an evocation change, though. I don't have Arcane Flows at all (none of my mages are arcane currently) and still don't bump into the cooldown timer enough to worry about it. I can understand arcane specs having a talent to reduce the cooldown, since let's face it, arcane can be a mana sink, but I prefer it as a perk to a spec that isn't all that efficient to begin with. Frost simply doesn't need Arcane Flows or any reduction, in my opinion, as it's already an efficient spec, same goes for FFB specs. Fire
could benefit, but it's not really needed (again, my opinion, and speaking mostly from an 80 perspective). No doubt it would help lower level mages, but Arcane Flows is not a 35+ point investment, 2-point talent for nothing even ignoring the other benefits of it. Making the evocation cooldown part of it more accessible or baseline would only make fire and frost more powerful and more efficient with no trade-off made...something which I just don't personally feel is needed and could potentially be overpowering in many situations (don't ignore the glyph as well).
Honestly, I like that mages aren't warriors, rogues, or warlocks, e.g. they can't just keep dumping damage as long as they have health. We've got more tricks and survival mechanisms than many classes, and a few ways to help us with mana both in and out of combat (much more than priests, for example). Blizzard has made some comments that they want to look at lower levels again with respect to the spirit changes, but I'd rather see them do that across the board and do something from that perspective so it benefits all mana users. As noted, I do like some of the ideas as a mage of both cap and lower levels, but I think those should be done to solve problems beyond the changes to spirit-based regen.