Wind direction and speed are more important than wave height.
This comment is spot on. It's all about having power to get through the surf. You can handle surprisingly big waves on a Hobie (certainly larger than 1.5 feet), but you need to have the right conditions. It could be blowing 20 knots, but if the direction is straight onshore, it can be very difficult to get out even if the waves are relatively small. On the other hand, if you have 10 to 15 knots side shore, you can generally punch through shoulder to head high surf without much issue.
The best advice is to start out on a day when all of the factors are more or less in your favor - moderate side shore breeze, small waves. It's also helpful to have another person hold your bow into the waves as you launch, especially if you're sailing solo. The most important thing to remember when sailing out through the surf is that you always want to sail directly into the waves at a 90 degree angle to their face. When you allow yourself to get turned sideways, bad things happen...
And that leads into your other question..
If you launch into big waves and capsize, do you risk having your boat damaged?
YES. Hobies are built tough, but everything has it's limit and flipping your boat in the surf will take your Hobie to that limit. If you're going to take your boat out in the surf, you have to accept that there is always the possibility you will be bringing it home in pieces.