To respond to a few of your points and share what I thought I saw from some of the players:
1.) Yeah, Martinez looks like a stud. Whether or not he's the starter in 2018, he obviously will be leading this team by 2019 or 2020. He has that special something that you see in a star college quarterback: he's big, he's fast, he makes good decisions, and he can throw in an above-average capacity. Oh, and he's only 18 and coming off of an injury. Dude is going to be a beast in the near future.
2.) I agree with your take on Gebbia, but I keep thinking of Mackenzie Milton when I watched him play. Small, squirrel-y, able to throw with a lightning-quick release, and able to scramble and run if necessary. I think he'll be a good QB, and I think folks saying he won't fit are vastly under-estimating his skills. He's not a big running tank the way Martinez looks to be, but he could definitely run an offense like this that hangs points on teams.
3.) We have soooo many options at WR, TE, and RB that I don't even think they merit discussion right now. This coaching staff has a ton of weapons to develop and they WILL use them to their fullest potential.
4.) I don't know what he did or how he did it, but Daishon Neal kept slipping by his blockers and harassing the QB's. That guy has definitely "taken the step" and moved up to a whole new level of play. I hope we use him regularly.
The only concerns I share with you are the penalties (there were kind of a lot, but you're right, they were mostly because the squads were shooting for speed and aggression and they're not 100% on top of that yet), and the defensive backfield, which seems to be the only unit where we seem thin and iffy.
Just my two cents!