Is the Jumu'ah (Friday) prayer and Eid prayers valid for a group of 35 Muslim employees who work at sea for 14 consecutive days, knowing that they combine prayers on Jumu'ah and Eid?

You are permitted to perform the Eid prayers and the Friday prayer. This is because the Eid prayers do not require a specific number of worshippers, so they are valid even if a person performs them alone. As for the Friday prayer, the more authoritative view is that a congregation is required according to common understanding, without specifying a particular number.