Re: 35 amp inlet breaker
Depends, to ere on the side of caution you can do a 30 amp and overprotect the circuit, but if you have a constant draw of over 80% of 30 amps (24A or 288watts @ 12vdc) then you are going to trip the breaker.
Going to 40 amps could be dangerous, however, depending on the gauge of the wiring running on that circuit. It looks like the wiring on the circuit should be a minimum of 14gauge at 12vdc to handle 40A. Also check to see what is on the leg, if the devices on the leg are individually protected by a fuse or internal breaker and you have 14 gauge wire, going with the 40A should be ok. If this breaker does not directly terminate to the battery, check any upstream wiring for possible load problems. And, of course, your battery will need to safely accommodate the potential extra load from the 40A breaker.
At the end of the day, though, you might be better off having an electrician check it out to make sure.