I think Guinan was going to be a Q/Trelane/Kevin Ukbridge/etc-like superbeing spending some time among the humans now but who ultimately had to be nomadic. Once her powers were exposed in some later season, she'd be off to someplace new.
If the El-Aurians were not to be quite as robust, what if Guinan herself wasn't El-Aurian? Maybe she was a shape-shifting lifeform of a sort...she shifted to El-Aurian and took on the characteristics and history and regret of an El-Aurian, but she was a more dangerous creature than Picard knew as Q said.
Or what if in the centuries of life since she left her fellow El-Aurians, she stumbled upon things in space that made her personally more dangerous? Maybe some ancient archive or energy being. Maybe she was Companion to Q's Dr. Who and she learned a thing or two from him.
If the El-Aurians were not to be quite as robust, what if Guinan herself wasn't El-Aurian? Maybe she was a shape-shifting lifeform of a sort...she shifted to El-Aurian and took on the characteristics and history and regret of an El-Aurian, but she was a more dangerous creature than Picard knew as Q said.
Or what if in the centuries of life since she left her fellow El-Aurians, she stumbled upon things in space that made her personally more dangerous? Maybe some ancient archive or energy being. Maybe she was Companion to Q's Dr. Who and she learned a thing or two from him.