I can find no reference to MySQL 5.15. AFAICT it jumped from 5.7 to 8.0. If you meant 5.5.x, then your version is out of support and you should be planning an upgrade.

Your Apache version number is not precise enough for me to tell, but if you are not on 2.4.x, you should again be looking to upgrade.

Your Perl version is not a problem (although 5.30 is available), but I found some years back that Strawberry Perl was more convenient on Windows than AS, although I used that for a decade or more. If you are using things that have been deprecated or removed in later versions, though, that is something to beware. Removals and deprecations usually happen for good reasons.

Source control is not a technical requirement, but most developers use it because they have the scars. The precise product is personal preference, but you may struggle to find developers who have never used git.

Editors, studios and the like are personal preference. You mention Visual Studio and I am pretty confident that you can use it, but what are the advantages that you expect from it?

I had never heard of Rose::DB before, but it seems to be a simplified version of DBIx::Class. I see no updates for three years, but that is not necessarily a problem.

It is a long time since I worked with the synchronisation tools of MySQL, but it used to come with lots of replication tools and I would be astonished if there were nothing built in to keep the two schemas in sync.

You are trying to run a business and write code at the same time. That puts a lot of strain on your priorities. But beware of masses of changes. Keep backups and don't change things unless you're sure that they won't cause breakages. This might be a time to do something cloudy - have your existing system running on one VM and your new one on another, replicating finctionality and doing a full scale parallel run. Cloud computing, of course, can be viciously expensive, but you might consider running a second hand server while major rewriting is in progress. Techbuyer are one supplier that I have seen at shows.

I won't go as far as to say that you shouldn't change anything that works, but such changes should always be made very carefully.

Regards,

John Davies