Exporting data then back end sql delete in sql table

So I started at a company 5 years ago. They were on Altiris CMS 6.0 and had a process which allowed them to have a sql dba export records into an archive table. Then go in and run same query but with a delete to remove these records.

This was done for a few reasons.

1. Patch management did not release license when machines were retired so when you delete they would retire.
2. Keep a smaller DB size for performance

Now I understand item 1. but I do question 2. I feel that doing a backend sql delete could create orphaned items and actually create more errors in the logs and also performance issues.

so Altiris still functioned and we went to a new server for CMS 7.1 SP1 but kept the same DB. Then went to CMS 7.5 Sp1 HF5 which changed the db schema and now we are on 7.6 HF7.

So I am curious as it is time to do another archive on other peoples thoughts or if they do archives how.

So few questions:

1. How big of a CMS DB will cause performance issues? 
2. Could this create orphaned items as I am thinking?
3. Could this cause actual performance issues?
4. Do you archive and how?

so our archived data is SWD records older than 210 days. We also archive computers that are retired older than 210 days. SWD records are deleted via SQL back end but the retired computers are deleted from the actual console. I think deleting from the console is the best approach as it will delete all records for that machine throughout and not create orphaned items.

Thoughts?

Thanks