Quote from: StephR on September 06, 2017, 11:41:11 AM

does electrum support all of these coins?

No.

Quote from: StephR on September 06, 2017, 11:41:11 AM

If not can you tell me what software should i use for each coins?

To everyone¹: Stop asking altcoin questions in this thread and questions that the first Google Search can easily answer, like "Monero Wallet".

Quote from: StephR on September 06, 2017, 11:41:11 AM

I just the safest possible..

Anyone who is asking any questions in this thread will not be able to have a setup that even remotely resembles "safest possible". "Safest possible" does not involve with you asking basic questions. In order to have such a setup, extensive experience and knowledge is require. Time to get some education on cryptocurrencies, no?

Quote from: StephR on September 06, 2017, 11:41:11 AM

Plus,if my offline computer crashes.. what are my options to recover my coins?

Backup the wallet files or seeds depending on the type of wallet on multiple machines/locations.

[1] Answers to such will be swiftly deleted.