I have an electrum standalone wallet for storing my BTC. I have three questions

1. I read that never store all your coins in one wallet. So wts the solution? should I install two electrum standalone wallets and store my coins in both of them?

2. I have written seed on a paper to recover my BTC in case my computer got corrupt. What thing apart from seed should I backup to recover my wallet in case my system is corrupted.

3. Strong password is good enough to secure a wallet or I have to do something else also.

Thanks.