I am back with more information,
I will be getting a full 5 years warranty and it seems to cover unseen damages caused due to loaning the piano that might arise these next years (that's how I interpret what's written)
the piano is in top condition, strings have nearly no patina/rust, action is sturdy and no new parts are required, Cappo d'astro is in good shape, uncracked soundboard, and the piano was even cleaned of dust recently. The technician confirmed that the piano is healthy and won't require any heavy maintenance or repair.
however, two problems were noted, both cosmetic. On the right side of the piano, next to the piano leg where the right angle is there is a slight ding revealing a bit of wood. it was a bump against a wall when moving it on stage. the second problem was underneath the piano, on a "black plank of wood" (unsure of correct term ) underneatht the key bed on its left corner. The paint has been rubbed off and the wood is starting to show. it was explained that this is due to the straps used to secure the piano when transporting it due to the many loading and unloading and was mostly cosmetic.
just to be more precise, the corner of the plank has no paint anymore and was "rounded", due to friction, with a bit of splintering but it seems to be superficial.
My technician confirmed to me that it wasn't unusual for a concert grand piano that has been loaned to have those injuries and that the shop explanation was coherent with what was presented to us.
after some discussion, we arrived at an agreement, the piano at ~38% off MSRP and all cosmetic damages of the piano would be repaired before final purchase and the approval of my technician after the repairs. Also piano cover, stool, delivery included.
I can still cancel my purchase but I am quite happy with the price and quality of the piano. I haven't discovered any defects big enough to drop the deal.