I'm the third owner of a 2006 Cooper. When I bought it the previous owner told me it had a front-end accident and had the bonnet replaced. But after driving it for around 8 months, I think it may have been a little more serious.

1. By the condition of the mini emblem on the steering wheel, I think the airbag probably deployed.
2. There is a wind leak somewhere around the windshield, so I guess it was replaced - and not all that well.
3. One of the headlight reflectors seems to be covered with dust (I don't know how that could have happened).

And to top it off, during my weekly wash today I noticed that the headliner is loose all along the front. Any good ideas on sticking it up to keep it from totally falling in the future?

 

Headliner issue that I had with my 2003 was very easily resolved with a $4.50 can of spray adhesive from Home Depot. Get the extra strength kind. Cover whatever you don't want to get sticky with plastic sheeting (like a painting drop cloth), spray both the headliner fabric and the headliner foam section with spray adhesive...wait at least 2-3 minutes so that the adhesive dries a little and gets tacky. Smooth it together starting from the inside towards the edge...it's not at all noticeable that I fixed mine.

Mini emblems getting messed up is a common issue but there is no way to restuff an airbag so I doubt it deployed. Jump in eBay and search for Mini Cooper airbag and you will see what I mean.

The other issues I can't help with.

 

+1 to the above...
Also when a windshield is replaced, the side pillar covers have clips on the back, and a foam or felt strip to block wind noise... A experienced windshield pro (on a mini) will bring a new set...there is about a 50% chance of breaking one....if the old Pilar cover is reinstalled wrong...say maybe some glue cause the clips broke...the foam strip can't be used...and it is noisy...the side pillars have been known to fall off at highway speed if not applied right....
But a simple window/door that is not aligned could also cause the wind noise...
Sorry about you finding dammage too late...but my bet is no airbags went off...a mini older than maybe 4years is usually totaled if there is an airbag deployment....the wings on the horn/AIT bag do wear when touched...played with...so bet that is the issue....
And on most any car..once the headliner fabric starts coming down...best bet is rip it off, and reglue it...trying to tack it in place is s loosing battle...the sagging simply pulls more down...