I hear both these arguments a lot in Ireland as part of "it's different here" pitches. I disagree with both of them.
On the first point, the absolute rate of interest is pretty irrelevant imho. It is all about affordability, not the absolute rate. Yes, UK rates were at 15% at the end of the crash period, but affordability rather than interest rates per se was the problem -affordability was going above 40% of net income. The prices themselves relative to income were lower than we have in Ireland today but because the IR's were so high, the net income percentage was high.
As many commentators have reported, we are now at the limit of affordability in Ireland, even though our base rate is 3.25%. So you could argue we are in a worse position, not a better one.
Second, 120% mortgages were certainly not readily available to everyday punters. 100% mortgages were but IO and other "exotic" forms of financing were not commonplace. BTL was also very rare.
My recollection is that 100%+ mortgages were marketed after the crash so people could "buy" their negative equity and move out of their homes.