What you have there is..........a lazy installer at the factory that had a hand full of crimps and some short pieces of tubing so he used them VS going and getting a couple of longer pieces to use. They are paid 'piece work' and going to get more tubing would take time.... :S
The tubing is 1/2" PEX
The fittings are put on using crimps (bands) and a crimping tool.
You have to cut them off.....cut them diagonally across the band almost into (careful NOT to cut into tubing) and then twist them off with pliers.
You can purchase a PEX crimping tool and crimps at most hardware stores (Home Depot/Lowes/ACE).....the bands are different retail then the ones you see used in mfg.
Other options.......Flair-it fitings, Sharkbites (Home Depot), Gatorbites (Lowes).
I prefer Sharkbites.......little more expensive but so easy to use (no Tools), don't leak, can be easily removed ('U' shaped tool--$2) and they WORK! Just make a straight/clean cut/no burrs and press them on ........done.
Here is info on PEX tubing and tools etc.......
LINKSharkbite info......
LINKAs for that anode rod in your Suburban WH......it did exactly what it was suppose to do. Sacrifice itself and protect the WH tank (Glass-lined STEEL tank)
Time to replace.........75% gone (just like yours)
AZ has hard water.......if you are gong to do a lot of camping in hard water areas (See map) might I suggest a portable water softener.
Hook up your water pressure regulator to CG faucet, then an in-line filter, then softener then to city water connection on RV. They use regular table salt to regen them (cleans the resin beads after they have collected the minerals---about 2 weeks. Takes 30-40 mins to do the regen)
Your water heater, faucets, toilet water valve, shower etc. will last longer/not scale up. OK for bathing, dishes but might want to use bottled water for coffee/tea. Not that it tastes bad it's just that non-dairy creamers clump.
We used one whenever in hard water areas. Works great.
On-The-Go and FloPur are two brands.