Using a SWM8/16 module with the legacy ports requires the four coaxes and there are SD receivers that work on the SWM system so you where maybe over the 8 tuner max of a standard SWM LNB and there was no new 13 tuner SWM LNB on the truck.
There should be a drip loop on the coax before it enters the house so the silicone is added protection.
I'm not an installer but I would not drill into vinyl siding. The power inserter can be anywhere there is an A/C outlet within 150' of the dish.