Okay GC; this discussion is still a bit tangled-up with terminology. Again, subs don't have internal crossovers; the speakers get a full-range signal even when they're connected through the sub. The low-pass filter in the sub rolls off the sub driver response above the selected frequency on the control(sometimes labeled as "crossover"), but has no effect on the mains. A very few subs have a separate high-pass filter, typically fixed at around 100Hz, on their speaker level outputs which affects the mains if they're connected in that way, but this has nothing to do with the sub's low-pass filter and its frequency control.
1. When connected to your 2235 with speaker wires, the sub gets all frequency content in both channels and the internal low-pass filter then rolls it off above 80Hz when that setting is selected.
2. Yes, the receiver power goes straight to the mains, regardless of whether the mains are connected through the sub. The sub amp can only power the sub driver; it has nothing to do with the mains.
3. Not familiar enough with the 2235 to discuss that "remote" provision, but again, use the speaker wire connection and don't worry about it.
4. Yes, shielding is essentially a non-issue with speaker wire. The current carried is far greater than that on line-level coaxial cables and isn't audibly affected by weak external interference.
