boltz-backend VS loop

This would only be possible custodial unless you run an own lighting node. Regarding the cashout to onchain cold wallet you can loop out lightning to onchain with literally any lightning wallet if you use a 3rd party service such as https://boltz.exchange/ or any other service that does the same job. Swapping to onchain can also be done using muun wallet but of course all methods cost the mining fee on top.

watch-only are on-chain wallets, so it will not accept lightning. unless you use muun wallet (custodial by third party) You can create a lightning wallet in bluewallet either by having your own node or adding it from a third party, getalby is a lightning wallet that you can add to bluewallet. After adding the wallet, lightning breez should accept the transaction, to send lightning to watch-only(on-chain) you would have to convert it or pass it to on-chain, https://boltz.exchange either https://learn.robosats.com/ they work quite well to move lightning to on-chain, keep in mind the fees can be high.

Also, look into swap services like https://boltz.exchange and https://fixedfloat.com

Today we’re introducing automation to LiquidOps, an intuitive interface to automate tasks for your nodes with workflows - it’ll restore liquidity in your channels with https://boltz.exchange/ submarine swaps and let you sleep at night!

I use https://boltz.exchange/ to loop out my LN BTC. Works great and it's the cheapest/easiest solution I've found.

I use Robosats exclusively these days and it's easy to send to cold storage using Boltz. Bonus points for boltz because I can increase the inbound liquidity of my Lightning node by sending sats to cold storage with them. You can do the same process they use manually but I've found that the fees are higher and it's less convenient that way

Swap out to a specific address using a service like https://boltz.exchange

I like RTL, services like loopd for channel rebalancing or if you're so inclined, the whole lightning terminal package. I love jochen's mempool explorer (source code) when estimating fees. I use blockstream's block explorer esplora (source) for my block explorer. There's so many fun tools out there I can't even come close to naming them all.

From https://github.com/lightninglabs/loop/blob/master/docs/faqs.md

I use RTL a lot but I have loop out problems in everything that’s why I use CLI. The command is easy https://github.com/lightninglabs/loop

This release packages LND v0.13.0-beta, Loop v0.13.0-beta, Pool v0.5.0-alpha, and Faraday v0.2.5-alpha.

No, you can also loop it out (https://github.com/lightninglabs/loop). It can use batched transactions to save on fees.

You can use loop in to refill channel with onchain funds. https://github.com/lightninglabs/loop#loop-in-swaps

You would have more details on why it failed in loopd debug logs. If you have access to cli, you can try using command check github docs for command options. https://github.com/lightninglabs/loop#loop-out-swaps

You don't have to close or open a channel to get funds in or out of the lightning network. https://github.com/lightninglabs/loop