Miners will still receive the transaction fees for all the transactions included in the blocks they mine. There's a recommended transaction fee formula built into the clients, but you set any transaction fee you want. Set it too low and some miners may choose not to include your transaction in their block, causing your transaction to take longer to complete. Thus, there will be incentive to pay miners sufficient transaction fees to make it worthwhile to process your transactions.

How long does it take a check to clear or do an ACH transfer? Longer than 50 minutes? In reality, you don't have to wait 50 minutes to be reasonably certain a transaction will complete. You can see the transaction broadcasted to multiple peers within seconds. For small transactions, that's probably enough. Usually a transaction will make it into the blockchain in about 10 minutes. At that point, the only way to invalidate the transaction would be for a miner to fork the blockchain by computing an alternate longer chain. Since there are many competing miners, in practice this would be very difficult. After a few more blocks have been added to the chain, it would be virtually impossible to reverse the transaction. For very large transactions involving thousands or millions of dollars, it probably makes sense to wait 50 minutes for multiple confirmations, but for smaller transactions it's definitely overkill.

I've interviewed lots of guys with 20+ years experience who have never really worked on anything very challenging and are basically at the same skill level as someone with 3-5 years of experience. Given a choice between a guy with 3 years experience and a guy with 20 years experience who are both at the same skill level, I'll prefer the guy with 3 years experience. Why? Because if after 20 years your skill level is the same as a guy with 3 years experience, your skill level isn't likely to improve. The guy with less experience is more likely to continue to grow and be more valuable in a few years.