Under most definitions of toxic that everyday people use, no. That would be if you were in the vicinity, you will not drop dead. Now if you snort the fumes from the tailpipe, the fumes will be toxic. In scientific terms, toxic means, will there be any impact, yes, you should avoid the fumes whenever possible. The fumes will have similar chemicals as found in car exhaust. The fumes are not good in large quantities and do contain carcinogens.

It is safe to be in the path of the exhaust. Only time it would be a problem is if you are in a closed room with a running engine for a extended period of time.

No more than any other petroleum based exhaust fume. They can ALL kill you eventually if you breathe in enough of them.

Not going to hurt you if you walk by and smell it. It will kill you in a confined space.

yes

yes but its short exposure means our body will not be unduly poisoned.