I would stay in Boulder the whole time.
You aren't far from Rocky Mountain National Park so you should go up for a day. In Boulder there is some great hiking up out of NCAR.
What's your budget because there are places to stay off of Pearl - Boulderado, St. Julien, etc., but they will be pricier.
The Tea House is worth it. Mexican - can't say we've ever found a good one in Boulder. Italian - there are a lot of choices. We've enjoyed Antica Roma for brunch, Bacaros is good, Pasta Jays food isn't off the charts but the atmosphere is good. Trattoria on Pearl is good as well.
Boulder Italian Restaurants and Pizzarias - Boulder Magazine Dining Guide Colorado CO - Italian Cuisine Pizza