Is the park very crowded on mondays and Thursdays?

No, until it's a holiday. Weekdays are best time to go with kids. Don't be afraid of long wait time. Just hop in between rides with shorter wait time to enjoy all rides.

No, I would definitely go thru the week, the weekends are the most crowded.

Ditto to the above. Decide what rides/attractions you want to do, do some research on when lines tend to be shorter and plan accordingly.

Always crowded and fun. Just plan for at least 3 day park pass.

It's crowded all the time, especially in the summer and during peak vacation times.