The only question not answered by the above posts was the one about how crowded are buses to the parks. That really depends on multiple factors. Where you are staying, where and when you are going and when you are coming back.
I would say at any
DVC resort we have not had to stand to go to a park, but we usually go to the parks for rope drops, lunch or an early dinner from the resort.
When returning from the parks at closing, after the parade, or fireworks then you will probably have to stand or at least wait for another bus. We have found that usually the bus rides including internal stops at the DVC resort or neighboring resorts to and from a park are between 10 minutes and 20 minutes. If traffic is bad between EPCOT and Magic Kingdom on World Drive it can increase the drive to 30 minutes.
Buses usually run every 20 minutes, but they get tied up in traffic and their schedule gets messed up. It seems the buses to DTD is the worse at every resort, I seems it always takes 45 to 60 minutes at least coming or going, alway delays there. But for the parks I would recommend that you try riding the buses to see what you think before dismissing them. We stayed at VWL this last trip and that resort has buses and ferry boats that can take you to MK. We have always taken the ferry, but this trip we took the bus. It was only a five minute ride! We couldn't have driven and parked and gotten to the gate in less than 12 minutes, maybe more because MK's parking is at the TTC. Even at AKV I think the bus is quicker for MK than you can drive mainly because you have to park at the TTC. But many of the other parks it's faster to drive but definitely not relaxing.
Also some DVC members prefer being able to walk to a park from a resort. BWVs and BCVs are walking distance to the International Gateway at Epcot (10 minutes for BCV and 15 for BWVs). They also are walking distance to DHS, probably 20 minutes for a family. But they also have the option of ride a Friendship boat to either park. But those resorts also share their buses with each other and the Swan and Dolphin.
BLT is only a 10 minute walk to MK, but shares it's buses with the Poly, and GF. You also can take the Monorail to Epcot and between the resorts and MK if you want.
AKV is a 5 minute bus ride from Animal Kingdom Park, but there is an internal stop between Kidani Village and Jambo House.
We usually drive to WDW so we always have a car available for use, but we often take the buses because sometimes it's not worth getting into a hot car or taking the trams out to the parking lot to get to the hot car. And after walking around the park all day, I just want to get on an air conditioned bus and be off my feet.