b. For the block to be accepted by the network it would have to contain at least 1/2 of all known transactions by the network (they would include more to be safe). It would have to have a certain % of free ones and and a certain % of paid tx's. Giving preference to the paid ones.
That's not a real thing. If there was a deterministic way to tell how many transactions were out there and what they were then we wouldn't need the block chain.
a. Block reward was always 25 BTC - no set max amount in circulation.
A big part of the reason a little piece of secret data can hold so much value is it's scarcity. I'd take a small chance on a currency like this if it was all that was available, but I put my life into Bitcoin.