Since your coach is a 2009, I would suspect age could be playing a role in your tire problems along with sidewall damage from the sun. Check the date code on the tires and start using covers on them. If they're China bombs, you may want to replace with some G614 Goodyears, or Michelin LT's.
A fulltime friend of ours in a toyhauler replaces one or two tires a year, but continues to use cheap tires and won't cover them. Unless you're under a bunch of trees in Lancaster, I don't know how you could only have a few minutes of sunlight on them daily????
I use this filter on our coach. Seems to work just fine, and has plenty of flow rate for our uses. I was changing the filter every year, but I'm changing every year and a half now.
Replacement filter around $120.00 thru JMS Marine with shipping included.
Load it up with a full tank of gas and 10 gals of water in the fresh tank and a couple gals. in the black tank and get it weighed at the scales. You can adjust the tongue weight when you know what it is.
I use an Equalizer hitch on our Wrangler/TT setup and it works great! No sway at all. Not with wind, or big rigs passing, either direction.
Setup your tongue weight, get a good hitch, and have a fun, safe trip!!