A mystic adept that takes the same priority for magic as a magician has the same number of starting spells, yes. He doesn't start with any adept powers. He has to buy them at 5 karma, or he can buy spells at 5 karma each. This is the same for magicians(minus adept power purchasing, of course). Gaining access to adept powers costs him the ability to ever astrally project.
Mages don't come even close to doing as much damage now. For direct combat spells, the DV is net hits from the attack. That's your (assuming high) Spellcasting 6 + Magic 6 vs. their Body or Willpower 5. So that's an average of 2 damage per casting. 2. In SR4, a direct spell dealt damage equal to the spell's Force plus net hits. That means a Force 6 spell with 2 net hits dealt 8 damage, and nobody casts spells at such a low Force in SR4. I normally casted at Force 9+, so that's a starting DV of 9+. Meanwhile, the drain for spells in SR5 was increased DRASTICALLY, meaning all Awakened characters will be casting at a much lower Force rating(although they'll always optimize so the drain is 2, since that's the minimum).
I apologize for not explaining my feeling toward your suggested change. To be honest, it's mostly based on my gut reaction. When I think about it further, it just seems to ruin the mystic adept completely. He suddenly becomes completely incompetent as either an adept or magician, with no redeeming characteristic to compensate.
As for suggestions or ideas, I have none. I think that, again assuming Bull's modified 5 karma price for power points is accepted, mystic adepts are fairly balanced. I believe that the reason most people think they're "overpowered" is that they're not awful like in SR4.
Thank you for clarifying, that cleared up a lot of what you meant. However, while direct spells have been greatly weakened, I find that indirect spells are a still quite useful and viable, which I think was the intention. Also, the new drain values mean that for a single target indirect spell, you take less drain then the 4th edition counterpart until you cast at force 12, which is even, or higher. The same applies for area abilities. So while I agree that direct spells are kinda crappy now, their still rather usable I find, just a lot more situational, while it seems that for normal combat, indirect spells seem more like what a person would do, especially with all the effects that can be applied. So I still think being a combat mage is very much within the realms of possibility, they just wont curbstomp people like they did before. That said I still think that making there be a DV minimum is a little silly, as it means that a mage is far more limited in how much spells they can cast.
I've gotten that feedback on the idea, which I created with the hope to keep MAs powerful enough to be viable, but not so powerful now, because I really don't want MAs to suck like they did in SR4, I love jack of all trades characters, but I think that at this point, there is no reason to be a mage. Here's my example: Say I wanted to play a mage, and I choose magic priority A. Now, I COULD choose mage, or I could choose magic adept, and get just pick up spells as if I was a mage. Now, somewhere down the line, say I decide I want an adept power, I can just pick it up, and go back to playing exactly like a mage, just with an adept power now. You see how this could easily be a problem? Someone can just play an MA like a mage or adept, but picking up the other sides abilities whenever they want, and while it may be a bit harder to get adept powers, they still are just as powerful as a mage, and can just play it EXACTLY as if it was a mage, with a few adept powers. If an MA started with a few less spells and such, then I think it would make more sense, but it is exactly the same, which I don't think makes sense from a mechanical or story standpoint (a mage who devotes himself to his mystic abilities would likely have more spells than an MA who did the same).
Even looking at the karma setup, a MA and mage can only have 12 spells with 6 magic, that is 10 karma, and then when a mage gets more magic, theirs spells can be a bit better, but when an MA gets more magic, their spells raise just as much PLUS the get adept powers, because after chargen an MA gets adept powers the same as a normal adept. If an MA started with 5 spells then they would need to really think about what they spent their karma on, but as it is, there is no real worry. As the system is now, mages only get better then MAs at magic as the game goes on, and they split their karma, but the MA is perfectly capable of buying the same stuff the mage does until an adept power would be better.
I've heard someone suggest that MAs be aspected in the magician side of their abilities, which would be interesting, but I don't really think fixes much. Another possible idea would be that the minimum drain would be 1 higher on MAs, but I am not sure if that is such a good idea, though it would make mages better at magic, it would take a silly idea like minimum drain and take it even further.