Need IT Advice: Club Member Management/Website/Forum

I'm on the board for a club that has roughly 500 paid members. The club has grown over the years and I feel the way that we manage our memberships, website, and forum has gotten outdated and inefficient. I'm making it my priority to revamp this system for 2019 and not quite sure the best approach.

Current Structure
We are using WordPress for our website. We do not use WordPress for any type of user management, only content.
We have a Vbulletin forum (Version 4.2.2). This is also how we currently manage our club memberships by using the Paid Subscription feature.

The Issues
I like WordPress for its ease of use and available plugins. While I am tech savvy, future board members may not be. The only thing that I think really needs updating here is our theme.

The forums are getting used less and less due to social media unfortunately, but they are a great resource for our club history and keeping records. We'd like to continue having a forum in the future, whether it be Vbulletin or some other software. The important aspect is that if we were to change forum software, I would want to be able to retain all database info (users, topics, posts) and import into the new software.

I feel like now that our club has grown to this size, Vbulletin is a very inefficient/limiting means of managing our membership. We have "members only" sections of our forum so it is convenient that new members gain access and expiring members lose access automatically. However, features such as mass-emailing, generating different reports to view incoming funds, new memberships, cancelled memberships, etc. are poor or non-existent.

My vision is to start using some sort of web based member management software. Ideally this software would integrate with the forum as a minimum so that we do not have to manually change access to "members only" section every time someone joins or leaves the club. I don't think we necessarily need the forum and WordPress to integrate as we don't use the "user" functions of WordPress.

Anyone happen to have experience managing this type of organization and could shed some light on the systems you all use to manage your club and its memberships?