LN on watch-only wallet: UX problems if I don't broadcast the funding transaction

Hi, while playing around lightning on testnet, I ran into the following issue: In a watch-only wallet, I was about to open a channel. But at the point where I should have switched to the normal HD-wallet to sign and broadcast the opening transaction, I wanted to change something, say spend a different amount. Since I had not touched my private keys yet, I was under the (maybe misguided?) impression that it's not too late for that yet. But trying to "cancel" the channel leads to unexpected behavior:

• Trying to close the channel will show the message "Please wait..." indefinitely.
• Trying to force-close the the channel gives a technical error message.
• I could remove the funding transaction from the history tab, but the channel was still shown. Moreover, the amount was then added to both on-chain and off-chain balances, as if I had doubled my money ;-)

I would suggest the following modifications for a more consistent UX:

• Do not allow closing or force-closing the channel before it is actually opened (at least the funding tx is broadcast)
• If the user removes the funding tx, substract the amount from the off-chain balance. Maybe put the channel into a kind of "cancelled" state? I guess it's not a good idea to delete the channel completely, since the user might already have saved the funding tx and accidentally broadcasts it later.

Start by reproducing the watch-only wallet flow described in the issue: begin opening a channel, do not broadcast the funding transaction, then try closing or force-closing it and remove the funding transaction from history. Trace the channel state and balance updates involved. Done means the pre-broadcast channel cannot be closed incorrectly, removal does not double-count funds, and the resulting state is consistent with the proposed behavior.