Is it possible to have too much religion and/or to be too religious? What do you think and why? If so what would that entail?
I vote yes.
When an individual's belief system is acted on without concern for another individual's or group's life liberty and pursuit of happiness,
Or
When an individual's belief system prevents acceptance of new information which would adjust their previous beliefs,
an individual has too much religion.
To put it another way:
Consider a person who takes their medicine
religiously. This person takes their medicine as prescribed, on schedule, without fail, without thinking about it, without considering the side effects, benefits, harms, or whether any positive effect is placebo.
Aren't some ideas worth dying for?
If I understand the spirit of your question, I vote no.
(
edited to clarify quoted question from OP not to change the words of my reply)