Are miners not able to cherry pick transactions to mine? I'd actually be willing to send like 250k sat or something as a reward for picking up my crappy zero-fee tx, lol...
Yes, they are if they are solo mining (and they technically understand how to do it). If they are mining in a pool, then the pool needs to pick the transaction (which some pools are willing to do, and others are not).
F2Pool has been known to do the exact thing you are asking for (confirm a transaction in exchange for an out-of-band payment) on multiple occasions. I'm not sure how big of a payment they would want for your 225 byte transaction. You could contact them and make an offer and see what they say.
I believe that pool is operated by a bitcointalk.org user that goes by the name of
macbook-air. You can try
contacting him.
I'm using version 0.12.1, so should I go ahead and just use the abandontransaction command or wait it out?
Be careful using abandontransaction. Doing so only removes the transaction from your own wallet. It does not cancel it on the network. Any network peer that has already received the transaction (including, but not limited to the recipient of the transaction) can rebroadcast that transaction anytime they like so long as the transaction inputs are still unspent. If you abandon the transaction and create a new transaction (with an appropriate fee) to send bitcoins to your intended recipient, and your new transaction doesn't use any of the same transaction inputs, then it would be possible for the recipient (or anyone else) to rebroadcast your original transaction (and pay a pool to confirm it). Then your recipient could potentially get paid twice from you.
To avoid this risk, you can take note of the current transaction inputs before you abandon the transaction, and then use the coin-control feature of Bitcoin Core 0.12.1 to choose at least one of those inputs for your new transaction. If you aren't sure that you can figure out how to do that, you could just send your entire wallet balance to a new address after abandoning the transaction. This would combine your entire wallet balance into a single brand new transaction output so that your abandoned transaction would no longer be valid.