I see nothing wrong with dating multiple people...IF honesty, diplomacy and integrity are made clear from the very beginning.
For example, when i traveled alone to Hawaii years ago, i was laying on the beach, and i was approached by a man who invited me to have a drink with him. i sat up, looked him in the eye, and i said, 'Let's make it clear right now: I am NOT a pick-up, I do NOT engage in sex with a stranger, and i do not drink. If you are comfortable with that,. I will join you for a coke."
I think anyone who is dating multiple people should tell the person, "I am dating multiple people...' from the very start.
That being said, your question, 'is it okay to date multiple WHILE SEARCHING FOR MR./MS. RIGHT? - i personally do not believe in 'searching' for a Mr./Ms. Right.
I think Mr./Mrs. Right most of the time comes as a surprise. My nephew spotted 'her' across the room at a party...they are now married. I spotted my Mr. Right in a garden chasing a little girl visiting his home; My daughter spotted her Mr. Right during a handshake in an office.;
MANY PEOPLE who have fallen in love have shared that when they first met it was instant chemistry. My best friend's daughter called her up and said, 'I just met the man i am going to marry."
I would find 'searching' to be extremely frustrating. I think those who just live their lives have great surprises in store...because when he/she meets Mr./Ms. Right, they won't even see it coming. It becomes a very glad surprise. Blessings, Sparklea :)