Fuel dot and switch mount usually go on RH side, somewhere between leading edge of wing and the back side of the cowl on my planes. Purely personal taste. Length of line leading to dot not important as long as it doesn't get hung up on anything.
72mhz not nearly as forgiving when it comes to functioning around things that spark or control/create sparks. Yes, it's possible to get them to work. It's not like we couldn't use ignition engines until 2.4 came out. 2.4 allows us to take many shortcuts you aren't going to get away with on 72. A single battery setup is an example of something I would approach with great caution if on 72.
I REALLY hesitate to make radio (or servo/receiver) suggestions, but since you mentioned the DX-6, it will work fine, but I'd suggest the Dx-7s wouldn't be that much more, and is much more radio for your dollar if you're buying a transmitter. Also, I'm using 7 channels on a plane like this one. Each control surface gets it's own channel (for unlimited potential when it come to slave and mixing setups), plus throttle and opto switch. The reason I hesitate is I've had pretty good luck with stuff others might call junk. I think a person's willingness to buy something like that depends on their degree of paranoia, and how affordable the aircraft they're working on might be? In any case, I don't want to hear about a plane that went in, or just doesn't work, using something I recommended.
Have a junk battery with heavy duty leads (that might have plugged into an ESC) laying around? That high quality stranded wire (usually w/silicone jacket) make great "tabs". Just cut an inch off and use that for your tab. If not, it's not like you need battery cable or anything. Any quality wire, maybe twice the size of what you plan on using for power leads, would work fine. -Al