Like Rich, I've never had interference issues with my electronics being on the same battery as my TM, but I have had too many instances of my electronics shutting off / rebooting when the TM hit weeds and bogs down, or the battery was getting to ~12.2 volts and I hit the gas 
So, now I have a separate "house" battery for all lighting, DF, GPS, USB, bilge pump and gauges and nothing ever drops out and the house battery only needs a "top off" charge from 12.4 volts after a full day of fishing. Night fishing in the rain, I'd expect a bit more of a charge, but my house battery is only a 35Ah U1 battery, a battery size I really like as a house battery because they are inexpensive, save a lot of weight and have a smaller footprint than large batteries.
Your current draw seems really high for your planned installation even in a worst case scenario.
For your nav / running lights you'd be really well served not only for reliability but a power conservation standpoint if you went with LED lighting. Current draw is in the dirt on them. Also an LED lightbar in the 25 to 50 watt range will draw 1/4 to 1/2 of your projected current needs. USB will draw no more than 2A and if you're using a Cig lighter appliance coupling they are (AFAIK) generally fused at 10a but unless you're actually lighting cigs, most anything today that uses LED's will draw well below that.
