I highly suggest the Rhino Flex sewer hose kit
. We bought one at the start of summer to replace our old hose and it works great.
The generator should do you just fine and it should run your air conditioner no problem.
As for the water pressure regulator, it is a commonly known issue in the RV world the you MUST use one. Unfortunately there isn't anything to back it up. As I stated in the other post about water hoses, the PEX tubing used in RVs is rated to 100psi and 180 degree temperature. RV pressure regulators guys use are pre set at 45 psi. Why I have no idea other than most RV water pumps are 45psi output. However you can buy RV pumps that are rated up to 65psi and they are used in the more expensive rigs. We upgraded our pump to the Shurflow Smartsensor 5.7 which is 5.7gpm and 65psi. We now have pressure at the shower that actually gets you wet, not just a 45psi trickle. Your plumbing connections can leak at pressure below 45psi just as easy and we have had it happen even using a regulator. I finally gave up on the regulator as you will be hard pressed to find a park that will have pressure in excess of 65psi. Those that just KNOW you have to use a regulator can't ever really explain why, they just KNOW you have to. It's a myth that sells regulators but doesn't really mean your system is safe from leaks.
My advice, use a regulator if it makes you feel good but you may be disappointed in the water pressure for showering. And check all your plumbing fittings on a regular basis as even brand new from the factory they may be loose.