Having it optional, sure
Having it required, nope.
These things should never be a requirement one way or the other for a myriad of reasons (some already listed) but always a possibility.
That's my two cents anyway
Also making a game with a suikoden-esque large cast. Here is what I do :
- Make every character unique yet every party combination valid.
- Have as minimal of instances where the player is locked into a certain party choice as possible.
- give every character a good backstory and presence in...
Worldmap Pro : sense of grander scale, being part of a larger world which in some stories is a necessary sensation.
Con : well you mentioned most xD
No worldmap Pro : more intimate and linear sensation, higher exploration and adventurous feel on a smaller scale.
Con : easy to mess up and feel...