re: Once these custom fields are created, can they be made searchable by other Members
Yes, it is possible but would have to be custom coded which would not exactly be easy.
re: Also, to make life easier, what Membership plugins work well with this plug in?
Sorry, I do not have any recommendations… I’ve seen people use all sorts of membership plugins. Generally the process is the same, user fills out, pays, gets password. After user is logged, the most common solution I’ve seen is that there is a member “dashboard” frontend page which gives the user instructions/links on how to do various task such as adding the entry and making changes.
Hope that answers your questions thoroughly!