do you get more points for testing out of a skill?
I remeber I tested out a lot of skills (i.e, using the 'key' icon to jumps up levels 1-5 on individual skills) and I received XPs equal to the number of lessons I would have completed otherwise to get to the upper level of the skills. So if there were 10 lessons on level 1 and I test out Level 1 to jump to leve 2, I receive 100 XP. If there were 5 lessons, I get 50 XP. But it seems like they have changed that now, so I get way fewer XPs than the number of lessons mentioned when I test a skill out.
Testing out of a skill: i assume you mean that link on top of the lesson page, that makes you go through a longer list of questions and in case of success, marks that skill as mastered. If you succeed, you get all the points you would have got had you completed each lesson individually, or if the amount is not exactly the same, the order of magnitude is about right. So 100's of skill points in a couple of minutes. Similar stuff happens if you go to the "lock" logos in the skill tree and succeed: you get 1000's of skill points all of a sudden (plus skills unlocked obviously)
I must say that the last time i tried these unlocking things was months ago, it might have changed...