How long would you take to endorse people?

Honesty is the policy. If you don't know them, have had no dealings with them, how can you endorse? Endorsement is a recommendation and you cannot recommend without knowledge.

As long the person has your desired resources. Or when asked to endorse as your daily activity.

The "timing" varies with each individual. I am interested in giving an honest endorsement, therefore I first have to interact with the individual over a period of time - get to know them better. If I find the individual is worthy of an endorsement, I will give it.

I find out who is worthy, I will support

I will read out the persons profile, skills and experience before giving recommendation. I am interested in giving recommendation for only the persons whoever i know, if i got a strange recommendation request, i will go through the profile fully before writing.

Of course takes time. I don't endorse everyone. Only people here I know better than others (from discussions, groups, chat, etc...)