Answer: It would be better for your crabapple if you stake it up straight rather than prune off the top. Set 3 stakes equal distances from one another and use ties to straighten the tree up. You probably won't be able to make the tree grow completely upright - they tend to be crooked and gnarly and that's part of their character.
The only way to know if your apples are ripe is to pick one, cut it open and taste it. If it is, you can harvest them all. If not, give them a couple more weeks. Enjoy!
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