Besides plantar fascitis, what are some painful conditions that feet can get partly because they didn't stretch enough?

Shin splints, . Shin splints and achilles tendinitis are common as well as capsulitis under the ball of the 2nd metatarsal head. Sesamoiditis can also occur as well as stress fractures. Finally neuromas can occur due to excess pressure of the ball of the foot due to tight achilles tendon.
Variety of condition. Plantar fasciitis along with other foot conditions such as tendonitis, ie achilles tendonitis, peroneal tendonitis, posterior and anterior tibial tendonitis are not so much from lack of stretching, but more from overuse. Certainly, you should warm up slowly before stressful activity. Increase activity slowly, stretch, good shoes and supports will help diminish tho opportunity for problems. Dr. L.