It is easy to dump a lot of money into upgrades, and pretty senseless to dump $500 into upgrading a $100 bike. So, just be careful.
There are photos on the internet of V2100 bikes with rear disc brakes fitted.
https://www.flickr.com/photos/wicked_photos/8553397846/
https://www.flickr.com/photos/wicked_photos/8424174454/
It appears as if the people who did that made a custom bracket that bolted into the triangle of the dropout, and is that bolt for a rack, or part of the dropout?
You also need a new rear wheel that supports a disc brake.
If you do it, expect to spend as much on the new disc as you spent on the whole bike. I'd just add a second disc, rather than trying to move it.
I'm not sure suspension is needed for on the road. There are lots of non-suspension forks available, and the exchange would be reasonably easy to do. However, upgrading your bike is like
I'd figure out a budget, and start looking for a good used road bike. There are some in the $200 to $300 range, perhaps even less... up to as much as you want to spend.