Hi Chris,
Are you in Boston, MA USA? If so, we must be neighbors!
1. With the ESC I bought (which has 6v BEC) can I plug my Traxxas 2215 right into that for power or do I need a battery pack for the RX? If I can connect it, do I need a futuba-to-BEC lead -- something like this:
You don't need a battery pack for the RX - just plug your Traxxass 2215 into the ESC and you'll be all set.
2. The ESC can support 4.8-12v batteries. Pardon my ignorance, but does that mean I can run any type of battery (nimh, LiPo, Gel Cell) within the supported voltage range of the ESC? Sorry, but all the battery types and voltages are bit confusing. Given the ESC, can I reuse the Nicd pack that came with the seaport?
You can't run Lipo (not without a lipo cutoff), but NiMh, NiCd, and Gel Cell are all good choices and supported by the ESC. Yes, you can reuse the NiCd pack that came with the seaport!
3. Based on #2, which battery type do you all recommend -- what are you using? I will be using the stock motor and would like decent speed with nice long run-times.
The battery that comes with the boat is 9 volts but you can run a 6 volt battery but it will be slower. Has anyone tried a 12v battery with this boat?
I was hoping to retain the hose and pump. I assume I would connect this to the RX, but the existing connector for the pump is a two pin with black and red wires. Can I just get a standard connector that would fit my Traxxas 2215 (matching the pin-outs) and plug it in to the RX?
No, the pump can't be plugged into the receiver - you need an rc switch in between the pump and the receiver. The easiest thing to do is get another servo and a fish out a micro switch from and old cd-rom or vcr and connect pump to the battery through the switch - the servo pushes on the switch and turns on the pump.
Have fun,
The Dickie Tug was a good choice!
Jeff