Can a married guy have a platonic relationship?

Is it possible? Yes. As for taking it too far, not sure what you mean by that or by even crossing any emotional dependence levels as I think this applies more to girls than guys.

Like many other choices and/or question in life it all comes down to the individual. Some will stray and some will always remain true to their loved ones. What nobody can answer or truly know is which category their partner will fall into as things can change from day to day.

I think it is possible, but very rare. It would probably help if they didn't find each other sexually appealing. It would also help if the friend(s) spent time with both parts of the married couple as well. It would help to keep them in the "friend zone".

I think it matters on attraction. If they are not attracted to one another, then they won't stray from their partners, but too much interaction, more than they spend with their girl/guy, then it might be a problem. As long as they don't get too "friendly"

I think its possible I feel like if the person married the wife may have friends that are girls they are just platonic friends of the hubby I feel is very possible