We have signed the paperwork already (unfortunately before I realized the problem).
The 900# hitch weight is with the WDH/bottles/battery installed.
The only way I can think to ease things is to have my wife/kids/spare cargo in our SUV every time we go out camping, and to remove my tailgate to lower my trucks GVW prior to hooking up.
As far as the TT is concerned (forgive me for my lack of knowledge, still learning things and the only way to learn more is ask) if I'm smart about loading and keep weight near the axle of the TT or slightly behind, would that help with hitch weight?