As Marcel pointed out, the key is to add your plugin as part of the solution. However, I do want to point out that most plugin projects will likely depend on the SmartStore.Web project, so that being the case you won't be able to set the plugin as a dependency of the Web project (VS will warn about circular reference). As such, it is important that you manually build the plugin and make sure its build output goes into the Plugins folder of the Web project (see other plugin project build settings on how to do this) before every debug run. Once your plugin files are correctly copied or updated, run the Web project in Debug mode and you will see your plugin being already available for install - no upload is necessary. Hope this clarifies.

This seems to be EF migration related. You really need to spend some time to look through the setup/installation,dB initialization, seeding and EF migration and the migration seeders code if you haven’t done so already.

I I did sever clean installs of 3.2.2 - local onprem, cloud, SQLce, SQL server, Azure SQL and never ran into these error. I speculate you were running the installer against an existing db that was created wirh an earlier release but the necessary migration was never done. Try a clean install by renaming the tenant the folder then run the site again.

With all due respect, I think the answer to OP's question regarding the EF approach should be Code First on. This is based on my limited review of your projects, so sorry if I missed something.