There's a reason a lot of beach houses have the appliance level on the 2nd floor. Even a lot of the OBX concrete block flat-tops, are getting a 2nd floor these days... except when there is historic value in keeping them, as is.
Tough call; steel studs which rust in salt air or wood that rots & molds from sea water exposure? If the contractor is local, I'd tend to lean on his experience and preference. If you accept that things need replacing on a shorter time-line in that environment then he'll likely go with what is easiest to refresh. Stucco is also susceptible to mold; it's holds pollen and sand in it's little pores and requires regular power washing with chemicals to keep it looking "clean". Tile might be the better option.
Windows are probably the most important part of a structure, as they are the most aesthetically pleasing but structurally weakest element. I like exterior, steel, roll down hurricane shutters. The slats fit into an enclosed track and will discourage the thief looking for an easy target - it would take tools and make a lot of noise to get through them. And the shutters can also cover doors. Steel won't get mishaped in the heat as quickly as aluminum, and will survive impacts better. These are typically rated to a Cat 3 hurricane. (All bets are off, when it's a more intense storm.)
The shutters on the exterior, also helps preserve the integrity of the mechanical functioning of the window, not just the glass. And the insulation - which is important if you're running a/c. Do you have power at the cottage? Those shutters are extremely heavy and hard to crank open manually. But it's easy to add a power switch to operate them. (You MIGHT be limited by your breaker box however.)
Power would also let you use one of those high-tech induction hot plates, instead of gas. I would prefer gas, and the 1 qt propane cylinders/camp stoves last a lot longer than one might think - but yes, you would need to stock back plenty of these cylinders - or get the adapter that would let you hook up to a 20 lb propane tank, like you use for a grill. Camping supply places will even have stove top ovens that seem to work well. (Like Cabelas...)
As for not schlepping all this stuff back & forth - it's extremely common to have an "owner's closet" in beach cottages to store your own bedding, appliances, cleaning/paper supplies, emergency kit, etc. It stays locked until the owner is there, all the time. Could be interior - or on the exterior of the house - but for say propane storage would need to be insulated and vented.
As for the theft problem... outside of an alarm system and a caretaker who's on the call list, along with the authorities... I got nothin'. I'm not sure which is worse - theft or vandalism - the latter being completely incomprehensible to me. This is one of two huge issues with owning property at a distance from "home base". The other issue is maintenance.
I didn't want to have to deal with either of those issues at two other properties. Ack - the opposite of simplifying my life! - so I decided to let both go. I might have kept the little cabin, if the opportunity to buy the land behind me didn't show up. But it did, and apparently someone had been watching for this cabin to get listed for awhile.
I'm still letting all that sink in and adjust myself into understanding that the property line isn't where it was anymore, when I bought this place. It's a huge adjustment for me... and I'm still basically thinking "small"... this one little spot I can see from the front porch and I'm just not able to really get out in the back 40 much yet. Too wet, too cold, and probably not very good cell signal if I get myself in trouble. (I don't think I will, but crap happens.)
