Schedule of events - help (too much open time?)

2 hours of open dance is pretty standard.
I think the entrance / first dance / welcome toast will realistically take closer to 15-20 minutes rather than 10. Also you can allot for time for guests to be seated after cocktail hour 5-10 minutes.

I agree with Keri, you should allocate more than 10 mins for introductions, 1st dance and your welcome toasts (especially if you and your spouse are doing 2 separate speeches/toasts, it will last longer than a joint speech/toast) and I would probably allocate more than 1 h for the buffet. Chances are the dinner portion will last longer. The wait in the line is always long, unless you're having a small,intimate guest list.

Same I agree with the others, I'd add on more time to the toasts. Other then that I think you have a great timeline.

We asked our sister to give an informal toast... well she wrote her speech and it was 8 minutes long! You could ask your speech givers to keep themselves only 1 or 2 minutes or a lot some more time. Other than that I think your timeline is really good. Cake cutting will be a fun breakup between the open dance. Will you have a DJ? They can make your cake cutting a big deal and have everyone join in betting if you guys will do the cake smash or feed each other nicely.

I think your schedule is fine!!