If you mean you can join on Friday ( be in oman by friday) and return on Sunday..I do not see a issue. Remeber, we will leave thrusday so half of the day will be kind of gone. You can book the same hotel, but I am afraid the deal will not be applicable to you. And if you want you can tag along with us for the places we will visit on Friday.
For me Eid starts on Friday so I am not sure what you mean by second day of Eid. I am ignorant on these kind of holidays that are based on the moon calendar.