I would keep it symmetrical, like Yardvaark has, but bring in the trees to screen that brick, like Dig Doug shows. You can grow Boston ivy on it with no damage to the structure. Wisteria can destroy a building.

A definite YES to the new porch column and railing. If your porch is less than 30" from the ground you shouldn't even need a railing although it may be your preference to have one anyway. Do like the idea of a garage door with a glazing (glass) in it somewhere. Perhaps the whole door could be glass? Good Luck!

Read the Housetweaking blog from early 2011 through 2016/2017 or so. Dana and her husband bought an old, ugly midcentury and DIYed it into a really cool space - keeping the midcentury vibe but not being 100 percent married to it and doing it on a budget. They've moved on to a different house but all the old posts are still on the site. https://www.housetweaking.com/current-house/

It's super cute! I assume that since this is near wineries, then this is a rural location -- meaning they will probably be spending some time hanging around at the house? When I'm looking for this type of Airbnb, I prioritize comfortable hangout spaces -- a nice patio with a gas fire pit and/or a big hot tub. Awnings to keep out any rain are a must (and will protect your furniture). On the interior, I think an open concept works out best. The renters are there to visit each other. Set it up so that people in the living room can see and chat with those in the kitchen. Be sure there is plenty of seating for the LR and dining room. That kind of thing.