There are a number of plugins that may fit your intended purpose, you should search the WordPress Plugins Directory to see if there is one that fits your requirements.
Assuming you are utilizing BuddyPress 12.5.1 and above, there is some basic documentation if you wish to DIY:
BuddyPress xProfile fields administration
As for Profile layout, depending of what you mean by “modify”, it may depend on the Theme you are using and any built-in customization capabilities that are provided by that Theme.
Any best practices to ensure compatibility with future updates?
This is a balancing act since updates to Core, Plugins and Themes are asynchronous. Some updates are breaking changes (Major releases) while Minor releases or Patches generally tend to maintain compatibility. Other factors are plugins that are no longer supported (could be supported today but tomorrow it is no longer supported). In the event of unknown incompatibility, you may want to have the ability to rollback Core, Plugins or Themes.
Your best bet might be to have a local development site for testing the updates or, if in the wild, a staging site for testing prior to pushing any changes to your production site.
Other community members may have other advice for you.
