I'm in the 300's (gallery level, not field level) so dugout-seat Bud Light vendors are not a problem. In fact, apart from ice-cream/frozen-lemonade we get very few vendors of any kind in my section.
Also, I'm in the front row of 312 - effectively obstruction-free, except when people leave or return to their seats (not a problem). And how much of the Red Loft/Porch/Stadium Walk is all-access? I've never been there, and no two people seem to have the same answers (although I have seen secondary ticket checks on the staircase leading to the Red Loft).
It's all access. All of it. I sit all over the park, using coupon codes or Stubhub, and I always get my food from Teddy's or Kosher Grill on the main concourse, and my beer from the Loft or the Scoreboard Walk. In fact, the restaurant is all access, so at lightly attended games, you can sit at the tables and watch. With my nosebleed 400 seats for Saturday, I don't plan to actually sit in my seat. If you want a beer from the Porch restaurant, just tell them that's what you want to do, and you don't have to wait in line.
The only reason I was in dugout seats was I got them for 35 bucks for the Thursday day game from Stubhub.