Welfare is a general index made up of a lot of factors. Social security is one factor...but, just set it at 80 regardless of the cost because it does have a big impact.
So, the first thing you need to do is either get an enterprise to build a corp, or build your own corps. Make sure the corp you build produces a product that is in demand.
Regarding military stuff, there is a very good chance that if you tried destroying weapons and then they came back that it is due to automatic ordering. If you do want to shrink you military, disband units and sell weapons (not ammunition as that just comes back) and yes, do sell them. Many weapons are in very high demand and will earn you some money.
Now, regarding corporations. I do have an enterprise on white giant, and I'd be willing to build in your countries if you need.