The video you post was about how to create a raw transaction, and that's other topic, after reading your posts i'm not sure what are you trying to do, but it looks like an onchain engine. You need to give more clear ideas about what are you trying.
By the way, if you wan a watch only wallet, you don't need bitcoin core for it, you can use commands like
to read the information form the addy direct on the web, that way you can avoid running the full node.
I like to run a full online node better and transact through it rather than trusting some website.
The video was to ilustrate how annoying ti is to do a raw transaction manually. What I want to do is have an online node with all of my balances in watch only, so importing the public key + the label to know from where these bitcoins came from.
For instance you get paid in bc1dfgdsghiihidhgiusdhguisui under label "Chipmixer signature campaign".
Now, that is in an offline wallet, so you can't know if the coins arrived.
The idea is to put bc1dfgdsghiihidhgiusdhguisui in an online wallet (by online wallet I mean synced full Core node) with label "Chipmixer signature campaign". Of course the problem is if you have 100's of different addresses with different labels, you would need to import all manually. I need to dump all this information at once. And be sure to not import anything sensitive in the online wallet, like private addresses or even xpub which I don't trust to be online.