As a S2000 owner i have to Disagree completly.
There are 4 solid jack points - each on every corner of the sills - that are made for jacking the car up or for Jack stands.
These are made of doulde folded, thicker sheet metall, welded to the sills and up to the task. I have used them often without Problems.
Plus, there are two jacking points at the front axle and the differential.
Sorry, but i seems you did something wrong.
The car is rigid as a closed car thanks to is unique "X-Bone" Chassis. The stiffnes of the body and the chassis is still seen as the benchmark for roadsters. I ride it over country raods here in racing mode with 100 Mph and it feels solid like a tank.
The sheet metall for the fenders, doors etc is thin, as usuall with Hondas. I dont have a single problem with it.
But hey, porsche sells fenders etc. in extra thin for double the price because saving weight = Racing!
The handling of the S2000 IS delicate, it is a car for motorcycle riders. This car is very sensitive about tires and air pessure.
You need a lot of feel in your Butt-meter and cat like reflexes. It is NOT a killer, but it is like driving "On razors edge" often. Honda has made the S2000 more forgiving over the years. There whrere at least 4 different suspension set ups from the factory over the production run of 10 Years. Every one more forgiving than before.
But hey.. it is a Sportscar, isnt it?
Here is video where a guy jacks up the S2000, you could see how sturdy the jack points at the sills are: