Hello,
Some years ago we developed a simple CRM on Clarity, using a bunch of set custom objects created for this purpose (this was for Clarity 7.5). We do not use the project object for that purpose, though.
The idea was to provide the costumer with a temporary tool while they migrate from an old CRM to a new one.
But the 'temporary' CRM worked better than the client expected, and they delayed the migration process some years, using Clarity as a CRM for 4 years (3,5 years beyond the initial plan).
Clarity has all the tools to build a functional CRM (with exception of some marketing tools, such as mass html mail editor and dispatcher, but they can be developed as well, with a little more effort).
Instead of representing an account as a project, you could create a new object to represent an account, and consider each opportunity as a separate project.
Then you can create a specific set of stages for this kind of project, following the opportunity with weekly Status Reports, track predicted benefits and costs that the opportunity may bring to the organization, register and deal with risks and issues, etc.
All you need to do is to create a field to link a project with an account, and maybe a new template for this kind of 'project'.
As an opportunity is something with a beginning and an ending, it fits more nicely to a project than an account.
Regards,
Roberto Barra