Quote from: Cryptopottamus on November 10, 2017, 06:53:23 PM

My understanding of the bitcoin core app is that I need to be running a full node which is not advisable on my macbook air.

It really doesn't matter which wallet you use when the transaction is already broadcasted.

Quote from: Cryptopottamus on November 10, 2017, 06:53:23 PM

My understanding of RBF is that it needed to be enabled from the wallet that I originally sent the transaction from (so too late for that I think).

Yes.

Quote from: Cryptopottamus on November 10, 2017, 06:53:23 PM

My understanding of accelerators is that they are hit and miss (and expensive with no guarantee).

The accelerators are mining pool so they will include it only when they mine a block.

Quote from: Cryptopottamus on November 11, 2017, 01:23:51 AM

This as I understood it, was a double transaction attempt. Now it keeps saying it's there one minute and not the next and keeps trying to push the transaction over and over. What's going on? Where are my beloved BTC? Please help shed light?

Since your original transaction had a really low fee, the transaction was not propagated well through the network. Its possible that Copay hasn't seen the transaction yet but the rest of the network has already and hence its hard for it to be relayed well over the network. What is the transaction ID of the transaction that you have used for sweeping.