An experienced player who wants to build a character with self healing ability should have no trouble at all IMO.
New guys... are a different story.
Race is a big issue.
some classes are more difficult than others.
to UMD or not to UMD; that is the question.
To dump Cha or not...
To take Skill focus UMD or not...
Let me mention that healing amp makes a huge HUGE! really BIG! difference.
And those who can cast spells need to decide how many feats to devote to healing. (max, Emp, Emp Heal)
and how many skill points to Heal skill.
(btw, self healing with spells takes a bunch of SP)
Enhancements. (deepwoods stalker for Rgrs for example)
Heal amp for humans. etc.
eventually epic destinies/twists
It really just has to be a priority.