Definitely check the tyre pressures. Once the suspension settles in the ride will soften up a little so give it some time.

Retro-fitting the standard (non-Sport) suspension components would be cost-prohibitive, IMO.

One option would be to replace the 19s with 18s. They are available as OEM. You may be able to do a no-cost swap or trade with someone. This won't make a huge difference but it will help.