Three inlets doesn't necessarily mean three engines. Some a/c have auxiliary inlets to allow airflow into engines under certain flight conditions, such as low speed or high AoA. But if the a/c does have three engines, I wonder what Western secret squirrrel propulsion guys make of that? Does it tell them something about the capability of Chinese engines, or lack thereof?
It's certainly big enough to be a long range, interdiction/strike aircraft, but if it is indeed meant to be stealthy, its weapons will have to be carried internally. This cuts down significantly on weapons payload as no munitions are carried externally. Again, the spooks are probably already estimating its internal loadout.
Another mission a long range, steathy strike aircraft could undertake is destruction of all the various combat support aircraft employed by the US. Transports, aerial tankers, command and control, electronic warfare and other such aircraft are huge force multiplers, and are very important considering the vast distances that could be involved in a Pacific War.
We've been able to keep those aircraft safe in recent conflicts, but the Chinese have been rumored to be developing aircraft whose mission is their destruction. A long range, steathy aircraft with a belly full of AAMs would certainly fill the bill. Even a big, not so agile tactical aircraft would make short work of unarmed support aircraft, many based on commercial aircraft designs.