Water *will* flow 500 feet, so don't sweat that.

Check the water pressure at the end of your five hoses and decide what to do there. Check the specs of your emitters to see if it's OK. If the pressure's still high, put a pressure regulator at the end of the hoses.

A hose end timer may not work right if the pressure's too low at the end of 500 feet of hose there, so you might to put it at the water source.

Backflow preventer should probably go at the water source, if the pressure holds up. Don't think it matters where the filter goes. Good luck.

I have a 300' run of 1.5" lay flat ag hose ($120 bought locally), run off regular house well (think 1/2 hp submersible pump). It supplies two areas of 5 rows about 160' each no problem. The lay flat hose was the least expensive compared to poly or other pipe. The size keeps friction loss down (meaning less pressure loss). You might want to use 2" hose for 500'. The water in the hose also acts as a reservoir. You could put a timer on end of hose at the tree plot before going to drip tape.