What to see in Panama: villages, beaches?

I posted a few questions recently about Costa Rica and Panama, since we're still hesitating between the two for a trip in July.

Our plan would be to drive up through Panama to Bocas del Toro, then fly back (a classic loop).

We have tons of questions, since travel blogs and sites are often so glowing, which is why we'd love to hear real firsthand experiences.

1-We're really drawn to small colonial-style villages. Are there any similar to Casco Viejo in Panama City elsewhere in the country? 2-Which island is worth the detour, and are there any paradise-like beaches (clear water, snorkeling right from the beach) outside of Bocas del Toro and San Blas? 3-Which coast is better between Panama City and Bocas del Toro?

We're traveling with a child, so we'll avoid anything like treks or waterfalls that are hard to access.

Thanks in advance if you can help us out! [:(]