Almost all the attractions have one line for everyone. So your party can stay together. When the
ECV does need to go a special route due to steps or a narrow passage you usually can take your party with you. I have seen up to 6 people in one party. But I'm sure there are exceptions.
Due to the age of MK and Epcot they seem to have more special lines then the other parks. The ECV can be left outside with the strollers if your BIL can tolerate standing in line. I ride my ECV right up to the boarding area and leave it there. It may be moved but CMs or my DH have always gotten it for me right after the ride.
The shows have special areas for the
ECVs. You usually stay in the ECV for these. They have seating for your party but it usually is limited.
I always take my key with me and never leave anything of importance in the ECV.
I like to have my ECV off the parks as well, to "walk" and explore other resorts so I rent from an offpark vendor.
There is a great deal of walking at WDW. So I would urge anyone with difficulty with walking to do themselves as well as the rest of their party a favor and get an ECV. Your trip will be better for it.
Have a great trip, let us know how it was!
Nanajo DVC 8/98
Offsite 5/78
Contemp 11/85
BWV 3/99
OKW 11/99
BWV 3/01
OKW 11/01