changing REMOVE SHARES to TRANSFER SHARES isn't working, any ideas?

As for why it didn't remove the previous Add Shares transaction, that's because the Remove Shares and Add Shares transactions were completely separate transactions with no connection to each other. You might know that you were moving shares from one account to another, but Quicken didn't know that. The only way Quicken knows you're moving shares from one account to another is if you use the Transfer Shares transaction type. But as jacobs points out, you might not want to do that in this particular case. (I don't have any experience with Roth conversions, which it what it sounds like you're doing, so I don't have a personal opinion one way or the other.)

For most people and in most instances, Roth IRA conversions are taxable events.

You cite a link to the backdoor loophole. Just make sure you're following everything precisely, or you can get hit with unexpected taxes or penalties. If you never had a traditional IRA, the backdoor approach works well. But if you have money in a traditional IRA and try the backdoor approach, it gets complicated, and there definitely are taxes involved because rollovers from traditional IRAs to Roth IRAs must be done pro rata. (You may know all this, but I'll state it anyway for anyone else reading this thread.)

For instance, let's say you have $93,000 in a traditional IRA. Now you want to add money to a Roth IRA and figure you'll try the back-door approach of adding post-tax money to your traditional IRA, then immediately converting it to the Roth IRA. So you deposit $7,000 in your traditional IRA, then transfer the same $7,000 to your Roth IRA. It hasn't appreciated any, so it's free of tax, right? No, because IRS requires your transfer to the Roth to be pro rated across all your IRA holdings. In this simplified example, you have $93,000 that's pre-tax money and $7,000 that's post-tax money. So with $93% of your IRA consisting of pre-tax money, 93% of your $7,000 transfer to the Roth IRA is taxable. IRS doesn't allow you to choose to convert only after-tax money. (Also note that IRA applies the pro-rata rule to your total IRA balance at year-end, not at the time of conversion.)

So again, if you have no money in any form of traditional IRA, or all the money in your IRA is post-ax money (e.g. you never claimed any of it as a tax-deductible IRA contribution) -- which is rare -- then the back-door conversion is slick and tax-free. But if you have pre-tax funds in existing traditional IRAs, any Roth conversion is partially or fully taxable.

Again, I'm not meaning to sound like I'm lecturing; I've just seen people think it's easy to escape taxes with IRA conversions and get burned. If you knew all the rules and you genuinely have a tax-free conversion, then good for you -- and it sounds like you're all set with Quicken.