Even the bay area gets a freeze from time to time, I'd be reticent about running them outside. Don't forget that no matter which method used, there will be wall repairs to be done afterward and the plumber will not do them nor include them in his bid.

Turns out that for our 60-yr old house, we have copper pipes being attached to galvanized pipes (interior). Apparently not ideal.

I assume you mean the developer con-game where all the below-grade and beneath-slab runs are cheap galvanized, while all the risers and stub-outs are copper, so the happy home buyer THINKS they have "all copper" plumbing, then decades later the galvi completely rusts away... SURPRISE!... the phookin' Bastiges!

ASIDE: I'm always surprised to hear about concrete slab construction in a seismically active area like SF Bay... always thought it would be too "brittle"...?

Do I understand that you also have a concrete ROOF, with zero attic space? Do you also have hollow concrete block walls (aka CBS)? These will really limit your options... OTOH, sunlight and weather will never ever damage exposed copper, painted or not. Careless roofers, maybe, UV rays, nay way.

Anyway, concrete slab is the norm here in So-Fla (Hurricane Alley), with a shallow peaked roof, and at least a small attic space, PLUS we don't have the freeze issue mentioned by first respondent.

Here, when the original (galvanized) pipes beneath the slab give out, the new replacement copper is typically just run straight up the exterior wall from the service entrance (which is outside the footer/foundation/walls), through the soffet (copper pipe painted to match stucco walls), and then branched off in the attic to where it needs to go. So except for that one main feed, the rest is out of sight. Same with output of the water heater, except it's vertical output is interior.

This exterior pipe run can be avoided if service entrace is outside of a utility room--or relocated there--since you can then punch straight through the block, and go vertical inside, typically right near the water heater, i.e. do all your ceiling punches and exposed piping in one spot.

New copper feeds for interior fixtures are fished down interior walls, but of course you still have to knock out some drywall to tie them in, and retire/cap-off the old feeds coming up through the slab. (Plumber ain't fixin' the drywall either!)

Outdoor hose bibs and pool showers usually result in more of the "dreadful" exterior pipe runs, again, unless it's outside a utility/laundry room.

Essentially, with Florida CBS construction, you can't run/hide pipes inside the hollow vertical channels of the block walls, because the wall is topped off with a solid poured-in-place concrete header, which starts below attic level. (In fact the roof trusses rest on top of--and are tied to--the top surface of this header.)

SUMMARY:
1) I would be VERY wary of Option 3, and it sounds like you are;
2) I would like more details on your roof, but I'd be very reluctant to punch any new holes in it... OTOH, you probably have stack vents and all sorts of other "penetrations" already, so...
3) Exterior pipe runs, if horizontal, and low to the ground, could be camoflauged with landscaping...? Paint to match in any event. And there's always those "architectural" (aluminum) channels used to cover bundles of conduits and cables.
4) You GOTTA have indoor plumbing, or the neighbors will say bad things about you, LOL!