return side leak mystery - several questions, just bought house with POOL, expertise needed!!

[ckrom]

just bought a house last september.

I have the valve off on the pressure side step jets, and these jets are plugged (since the pool leaks water at a significant rate if the valve is open for step jets)

I had someone pressure test the lines (expensive $300). The suction side is fine, while pressure side had a 'major' leak. I think he said like 4 psi a second.
I mentioned to only test the wall jets, but maybe he did both and recognized the existing step jet leak.

When I run the pump I have a few issues:
I believe I am losing about a 1/4 inch a day when pump is running for 10 hours, would this indicate the pressure side leak described above? (dye test indicates no issues anywhere else, no water loss when pump is off)
Where are pressure side leaks usually located in the plumbing? I am potentially looking to have another leak expert find the exact spot of the pressure side leak (if it exists - it is expensive), and am concerned I will have to rip apart all my pavers and do the whole plumbing.. would rather just fix the one spot
Air going through the suction side / return jets spitting out some dirt and air bubbles - what could cause this? water is well above mid level on skimmers

Separate Question:
Too much DE ran through filter, now its all over the bottom and water is cloudy - how do I clear this up? Can I just brush it up from bottom and let it filter through?

 

[ckrom]

also - i ran the dye test on the wall jets when pump was off and none of the dye was sucked in

 

[ckrom]

update: 1) pool guys replaced the 3 valve on the return jets - gasket was chewed and worn out - which may have let water into the step jet line when pump was running
2) spider gasket on multiport was also replaced since it was worn out.. previously i was getting water in the look through glass while on filter mode - so water may have been leaking into the waste / backwash line while running in filter

between both of those fixes there is no more leak!

also - i was getting half prime on the pump - my DE filter was extremely dirty and not allowing the pump to prime - that was cleaned off with a hose and no more issue (tons of dirt was previously in my pool from powerwashing)