No, they are not "electrum officers"... as you yourself have already indicated here:
Electrum-LTC is a community-maintained port of Electrum, the Bitcoin wallet, to Litecoin. It is not an official product of Electrum Technologies GmbH, which does not support it
Official Electrum is BTC only... they DO NOT maintain or support ANY of the Electrum forks (Electron Cash, ElectrumG (BTG), Electrum-Dash, Electrum-LTC etc)
so I would like to know if they are safe or not
As long as you're downloading official versions of these wallets (and check the digital signatures and file hashes etc), you should be OK. To my knowledge, no-one who has used "official" versions of these wallets has had coins stolen because the wallet leaked seeds/keys. Generally they get stolen because of keyloggers, malware or users having been tricked into downloading and using fake versions of the wallets... or they do something dumb like enter their seed/private keys into a website to claim to try and claim fork coins.
another is electroncash that is not official and has bad comments
There was a lot of fear and "fud" surrounding Bitcoin Cash and the various wallets released for it. Obviously, a lot of thieves saw an opportunity to steal a lot of BTC (and BCH) after the fork by tricking a lot of confused users into downloading scam wallets that stole seeds/private keys.
The initial release of Electron Cash did a REALLY stupid thing... and "copied" any existing Electrum wallet files found on the computer into the Electron Cash wallet folder... The idea was to make it "easy" for an Electrum user to get their BCH and it did NOT steal seeds/private keys, but it freaked a lot of people out and made a lot of people nervous.
Added to this, that Electron Cash was the only SPV wallet available for BCH... it was very popular with people wanting a quick easy way to get BCH... so it became a target for the scammers (just like Electrum)... there were a lot of fake Electron Cash websites setup that were distributing fake versions of the wallet designed to steal seeds/keys.
I would like to know if it can be used apart from electrum, electrum.dash and electrum-ltc in the same pc without problems?
They can all be used on the same computer... they all use their own data directories, so do no interfere with each other. I have personally used:
- Electrum
- Electron Cash
- Electrum-ltc
- Electrum-dash
- ElectrumG