You can respec a Lone Wolf character, and you keep the extra ability points. If you do not take Lone Wolf again, you can recruit a companion or henchman.
In the EE you can trade an unused talent point for 1 ability point, so it is a bad deal unless there are no other talents you want (All Skilled Up gives you 2 ability points) or you can't get another ability point elsewhere and only need one to level something up or open up a new skill group (for access to the novice skills).
The full respec causes the character to unlearn all of their skills (other than a couple special ones like Staff of Magus), so you would need to replace any you still wanted to use. Keep an eye out as you level if you are planning to respec, so you can find the rarer skillbooks (or in some cases the scrolls to craft skillbooks).
