1. Can i transfer my BTC from paper wallet to Electrum(leaving BCH on paper wallet breafly)?
2. After this immediately transfer BTC from Electrum to Ledger Nano S .
3.Wipe out Electrum programm i used from my PC .
4. Install electroncash wallet on the same PC.
5. Transfer BCH from same paper wallet i transfered BTC to electroncash ,and the immediately from electroncash to same Ledger Nano S.
Yes. Honestly, it isn't entirely important to wipe your Electrum, considering that you are not going to use it. But hey, doesn't hurt.
So basically split my pre-HF BTC and move them to Ledger wallets.
Does Ledger support BCH? If not, you will need to export the keys into another wallet that supports it in the future.
If i do what i said in 1 ,what is better to import or sweep privet key to Electrum wallet ?
Import. There's no need to sweep it unless you are going to be using Electrum as your wallet.
And, if i sweep/import BTC from that paper wallet do i still have same ammount BCH there ?
The same amount. Only the BTC is transferred using a BTC transaction, the BTC transaction isn't valid on BCH and the BCH will not be touched.