You have to remember that any binding can break given enough stress, so that statistic about markers breaking once you hit 150 lbs is simply not true. While there may have been instances of marker bindings breaking under someone who's 150 lbs, there are infinitely more cases of people who weigh more than that and are doing just fine. Almost the entire nimbus crew uses jesters and they charge harder than almost anyone on this site will ever be able to. That being said, although marker has stepped up their game recently, markers do have a shaky history, and their bindings are made of plastic. Also their afd piece is movable, which isn't as desirable for park. Although at 5'1" I don't see you having any problems with your jesters (why aren't you riding griffons, btw?). So I guess your answer is, yes they will be fine for park. Not outstanding; there will be better bindings out there, but there will certainly be worse. If you're looking to upgrade your bindings, I would trade those jesters for some sth 14 drivers, or even 12 drivers at your weight. FKS are also always a great choice, although they can be annoying for hiking, and if you have a tendency to break brakes, they aren't the best because you have to disassemble the heel to replace them. People will tell you that you can explode the plastic toe piece on the lower din FKS bindings, but that's very rare, and basically impossible at your weight. I'd go for an FKS 120 or 140 at your weight. I rode 155s on my hellbents all year and they were fantastic. The 155s have the burlier, all metal race toe, but even with the plastic toe, the 140s will still have plenty of burl for your charging needs. Tyrolia/Head/4frnt bindings are good. The Peak/Mojo/Deadbolt model would world perfectly for you. If you went that route, I'd go for the 13 or 15 din model. Best din range for your size. Anyway. Have fun, and don't max the fuck out of your dins because it makes you feel cool; your knees will thank me at the end of the season.
-Isak