I just setup a Firebase Hosting and deployed it.
My question is, can I use this hosting as a cdn to load content on my other already published site?
Is this a good practice?
Also, is there a limit on firebase hosting requests?
If for e.g. there are too many requests to a particular file type, does it still work or will it throw any error?
Firebase hosting is advertised by Google as edge optimized SSD storage in their CDN infrastructure. Google's documentation suggests that this is a supported use case.
If you are already using firebase, that should work for you. Implement, measure. Keep measuring as traffic volume and patterns change.
If it isn't meeting your needs, move to a different CDN solution.