In order for Noah's arc to be possible ....
John Woodmorappes book covers all those questions, the issue of space is not a problem, as the ark was quite large - the capacity of 500 railroad cars.
There is a plethora of websites covering these issues, but IMHO most are paraphrasing the book (whether intentional or not i do not know). Not to mention the website linked in the first post on this page has detailed explanations as good as any. I suggest a google look and then address the real 'plot holes';
1. Logistics of feeding, cleaning that many animals by 8 adults.
well that is the only one that I have issues with.
You are right about it never being found. There is two points i would like to make about that;
1. they are not looking in the right place, after the flood, indications are that people moved to Babylon from the east (not modern day Turkey in the north) Gen 11.1
2. The instructions for Ark building were to cover it with Pitch inside and out. Gen 6:14 It only needs to be waterproofed from the outside, so the suggestion is that this was done to preserve it.... God's plan is for it to be found one day.
Mountains to the east of Babylon are fairly desolate places, and who wants to go to Iran these days anyway, certainly not Ron Wyatt