A dehumidifier typically has pressures above 200PSI (250 on hot days.) Most HVAC stuff is rated to a minimum of 400PSI.
you should be fine.
Yes, the 2" riser is common as it slows the air down and has a large surface area to cool the air.
I get very little water in my lines; mainly die to having a large compressor. I have a low outlet that catches the water. My line is about 20' long and all 1/2 copper. I get new no water in the traps on the filters.
A good water trap uses a venturi and swirling effects to cause change in pressure and temp locally to cause the vapor to condense. Those cheap filters mentioned do not have anything; just catch water already condensed.--
Embedded Systems Consultant,
SHDesigns home - DIY Welder