A few points:
#1.
Is it really as simple as opening an IRA, putting the cash in it and immediately moving it to a Roth? Can it be done completely online?
Yes, and Yes. Though there is typically a 7 day period for the money to clear if you are transferring the money in from an outside institution.
So, a couple clicks to transfer the money into an IRA. Wait 7 days for money to clear. A few more clicks to move it all into a Roth.
#2
If you have any IRA balance with pre-tax money, you will have a huge headache with this. You cannot do a last-in, first-out type IRA contribution and then backdoor it into a Roth. Any conversion to a Roth will have to be done
Pro-rata.#3
Do you even need to backdoor roth? Can you do a normal roth? In most situations, if your income level allows you to deduct your contributions to an IRA, it's also low enough to directly contribute to a Roth IRA. Of course, special situations may apply.
#4
If your tax guy doesn't know this basic info, what else is he missing?