Well, got everything built in the last three days, let it sit overnight and did a full system test using 1.5" flex hoses run to my 650gal hot tub as a water source... I ended up using all 2" fittings everywhere with the 1.5" connections at the pump... I also went with Jandy 3-way and check valves along with NDSPro ball valves/flap check valve for the heater backup protection...

Everything tests out great!

I noticed about 9.5psi of backpressure at the Sta-Rite System3 cartridge filter with the Dynamo 1.5hp pump on high... I also noticed that once I switched in the heater it basically added about 2psi of backpressure...

With the Dynamo on low it showed about 2psi of backpressure...

My Jandy Lite2 millivolt 250k btu heater worked great too... Started right up and heated the water great... I noticed that the 2psi of backpressure on low was enough to allow it to operate so I will have to check it once the entire system is plumbed in with 2" out to the pool and see if it still has the same pressures... I doubt it will... But in either case I will adjust the pressure switch to make sure it only comes on once the pump is on high... (I even considered a small 120v relay installed in the pump that would kickoff only when it was on high tied into the firemans switch loop as well, but we will see how it goes)

My water feed with check and ball valve worked great as well...

I let the entire system run on high dumping the first couple hundred gallons of water to flush out all the piping and the filter/heater/etc...

In the end I am just happy I have no leaks anywhere and everything works as expected... Now to get the skid steer here and get the pool built!!!