Best Way to use 1Password along with other security mechanisms ?

Thanks for great explanation.. Appreciated.

You also omit the most widespread and basic mechanism: username/password.
This is of course the best mechanism when it comes with a Password Manager.

Thanks for SMS security issues explanation.

Again Pros/Cons of using MS/FB/G accounts for login to sites..

Quote from - https://blog.1password.com/passkeys-2fa-totp-differences/

If you want the protection of true 2FA, your one-time passwords need to come from a different device than the one that holds your account passwords.
TOTP according to you is still best, I find no difference in TOTP codes stored in 1PWD and/or using logins without TOTP. (when account is compromised)
But yes in case of website breach, TOTP is the last savior (biggest advantage is todays world)

A.
Passkeys being the most recent, will wait for your inputs here as well

B.
I have at present all the backup/recovery codes for 2fa into there respective logins, any suggestions for this ?

C.
I agree with this - https://blog.1password.com/why-trust-1password-cloud/
Which combination is more secure alongwith 1PWD ?
*1PWD + 2FA or 1PWD + Passkeys or both ? *
I want to implement the best which can be easily accessible on cross-platform. (Windows and Android at present) for few important sites.. rest can go with any.