Let's take this in pieces:
Social security: What does "paid for entitlement" mean? All entitlements are paid for. Whether by tax payers or by debt that is then funded by tax payers. In the current world, because your benefit is derived from your contribution, you could say that social security was not an entitlement. I would disagree because there isn't a direct link between the benefit and the contribution (otherwise it wouldn't be in danger of insolvency in the first place), but that's for another day. For now, if you remove the link that is there by saying that contributions should far out measure benefits for some segment of the population then I don't see how it is anything but an entitlement.
Food stamps, Medic-aid, other welfare programs are paid for by taxes. SS is funded by a specific tax that is paid to pay out this benefit. Initially, your taxes pay for current beneficiaries.By the time you are getting it taxes from others are paying you. It was ALWAYS meant to be an entitlement, but one that paid for itself.
Dividend income: Let's assume a theoretical world where a high level executive works for a firm with a corporate income tax rate of 25%, pays a personal income tax rate of 25%, and there is no difference in taxes between salary and dividends.
For each $1000 of salary, the government receives $0 from his company and receives $250 from him.
For each $1000 of dividends, the government receives $333 from his company ($1333*75%=$1000) and receives $250 from him.
This is the same circular gibberish that says the customer pays corporate taxes not the company.
It's totally IRRELEVANT what the corporation pays in taxes when you are talking about paying an employee in dividends. They are two different entities. They aren't the same and never will be.
The dividends are taxed more. That isn't sidestepping; that's math.
Capital gains: I am afraid I do. The value of a financial asset is based on its future cash flows. If corporate income was tax free then the cash flows would be larger, the asset would be worth more, and the capital gain would be larger.