EDIT: If no also, would 1 in 2,176,782,336 be enough or still no?
But to answer your question, In in 10 000 000 000 would work well.
1 in 10 000 000 000 would still be cracked insanely fast.. You need big numbers with more than a 100 zeros to get safety from collission.
Luckily, that's exactly what bitcoin provides. And even when you get a collision, the address most likely does not hold any coins.
Nope, even if we assume full 256 bit there are only 78 decimal digits. For an unused (for paying, not receiving) address we can assume 160 bit (due to RIPEMD160) and for a used address 128 bit (due to ECDSA), so 49 and 39 decimal digits respectivly. If you must have 100 decimal digits to feel secure, bitcoin is too weak for you.