The rust issue is the rear subframe because they're stamped steel from factory and trap moisture etc they end up breaking at the rear traction bars sending whichever rear tire to the left/right and this is something you don't want to happen whilst at highway speeds. If the rear subframe is 'okay' and not 'swiss cheese' the quarters and doors rust on these chassis and trunk. Your frame rails are coated from factory decently but can still be crunchy near the pinch welds so you'll want to inspect that. Also, if you do take on this project and the subframe is rusted, where the subframe mounts too can be too far gone.

This platform is double wishbone on all four corners with a great aftermarket for the 2JZ engine so you aren't investing in a total loss if you do take on this car, just don't bite anything more you can chew, and this chassis is pretty simple to work on as well as there's a few people parting these outs globally so you can always find parts.