Yes, you generally need to pay taxes on realized gains even if they are reinvested. Capital gains tax applies to profits from the sale of assets, regardless of whether those gains are reinvested. The tax rate depends on the holding period: short-term gains are taxed at ordinary income rates, while long-term gains benefit from reduced rates
Yes. A reinvested Dividend or Capital Gains is really 2 transactions. Just like if they sent you a check for it and then you bought more shares. So be sure to add it to your cost basis when you sell the shares.
Unless it is in some kind of retirement account like a 401K or IRA. Then you should not get a 1099Div for it and it is not reported or taxable.
I know, doesn't seem right, does it? But I talked to an attorney at my trust company (who paid the realized gains) and she assured me that yes, report it as income now, but that money (or amount) will NOT be taxed again when it is paid out. Hope this helps.