if you can get around bout ten people standing in the spot of the tank, then it will more than likely be fine. my juwel rio 400 is upstairs and no problems, but i am cautious about adding to many rocks.
confish water weighs 10lbs per gallon,so your tank would be like two large 315lbs men standing side by side[with about another50lbs or so in their hands]meaning gravel,filter,heater and other accessories.You should not have to worry.
Not sure quite what you mean?
what i do is i get another filter to run your current tank, let that one run for a week or so, then move your established filter into the new tank or just take the sponges out and put them in your filter box. then let that run for a week or so, and slowly move your fish over.
tbh i have seen people do this in a day, but i like to be sure, but i'm sure if you could get enough established media in your new filter then you should be ok.
its best to make sure that it is placed near a load bearing wall and goes across the floorboards instead of in line with the floorboards to be on the safe side
want want want!!! thats what i think, nice tank man....if only i could afford it....