Ignore this if I am mistaken but… the questions you are asking above tell me there are some misconceptions or misunderstandings regarding how accounts work on the Flow block chain. I would highly recommend reading this post: So, How Are Accounts on Flow Different from Accounts on Ethereum? | Decentology by lovely people at Decentology about how Flow accounts are different to Ethereum accounts. Many people have these sorts of misunderstandings regarding Flow accounts, especially if they are coming from an Ethereum world, so you are definitely not alone in the line of thinking you were going down, but you will have all sorts of issues if you continue down it with Flow.
As @unlocked mentioned you are probably looking for FCL, it will allow you to support multiple wallets with out you needing to do any work on your end. You can see it in action at: https://port.onflow.org/