Very good questions that I hadn't thought about.
What if it we aimed for 0,5% inflation but spread the spoils based on how many transactions were included in that block? Of course this would give the miners a real incentive to spam the network with transactions. But what if we required some local proof of work for each transaction, that the clients were expected to do themselves. Like hashing the transaction data with different salts until a salt with x number of zeroes in the end was found? Then this salt could be added to the transaction data for others to confirm easily. Each transaction data together with its salt had to be unique, so you couldn't spam the network with the same transaction. This local proof of work would also have to be less profitable for miners than just mining transaction proof of work made by others. That shouldn't require much, since you would be unlikely as a miner to receive the bonus for your bogus transaction anyway (win the block). Spamming would be very computationally intensive and spammers would in effect pay by loosing potential income from not using that computational power to mine.
As for if this is for bitcoin, I don't know if it can be implemented at this point with backwards compatibility. It would probably take a lot of work. Seeing as you are a moderator feel free to move the post if you feel it belongs in the other section. But please also feel free to continue to provide valuable feedback
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