Nothing much new here - this build for a LR for a broken build, but have to move Cleric to 6 to accomodate. Also swapped in Barb (@ 8) vs. Fighter (@ 12) for better kiting. Losing Rapid Shot is a small loss in DPS (it does not improve fire rate as much as advertised), and "faster kiting" can be more of a life saver imo for a newer player.
(If I were using this from Level 1, I'd suggest Cleric at 2, Barb at 4, for earlier use of both. The 7 Barb skill points would go 3 into Jump, 2 into Heal, 2 into Spot.)
I held off on Open Lock in favor of keeping Heal as high as possible - swap out Heal points for OL if you're running in to trouble (but w/ good gear, you shouldn't, just might have to keep trying until you roll high-ish).
Note - I changed one important thing from the original. I hate the feeble starting Str of 8 on a Halfling for a new player, but that's what the original had. Makes a Strength item mandatory or you lose Evasion, can't pick up heavy loot (when every item is badly needed cash), etc. etc.
This build doesn't take IPS until Level 18 - so if you can get 1,750 Favor before then, you can drop Dex by 2 and increase Str by 4 (all the way up to 12!), and grab a +2 Dex Tome then to make up the diff. This change is recommended, but not mandatory.
The original* had starting Str 8, Dex 18, so didn't rely on the +2 stat tome. Ymmv.
(* & see that post for OP's full notes, enhancements, destinies, etc.)
Self-healing Halfling Mech (w Cler @ 6)
18/1/1 Rogue/Barbarian/Cleric
True Neutral Halfling
Level Order
1. Rogue. . . . . .6. Cleric. . . . .11. Rogue . . . . .16. Rogue
2. Rogue. . . . . .7. Rogue. . . . . 12. Rogue. . . . . 17. Rogue
3. Rogue. . . . . .8. Barbarian . . .13. Rogue . . . . .18. Rogue
4. Rogue. . . . . .9. Rogue. . . . . 14. Rogue. . . . . 19. Rogue
5. Rogue. . . . . 10. Rogue. . . . . 15. Rogue. . . . . 20. Rogue
Stats
. . . . . . . .28pt . . Tome . . Level Up
. . . . . . . .---- . . ----. . .--------
Strength. . . . 12. . . . . . . . 4: INT
Dexterity . . . 16. . . .+2. . . .8: INT
Constitution. . 14. . . . . . . .12: DEX
Intelligence. . 16. . . . . . . .16: INT
Wisdom. . . . . .8. . . . . . . .20: INT
Charisma. . . . .8. . . . . . . .
Skills
. . . . . R. R. R. R. R. C .R .B. R. R. R. R. R. R. R. R. R. R. R. R
. . . . . 1. 2. 3. 4. 5. 6 .7 .8. 9 10 11 12 13 14 15 16 17 18 19 20
. . . . .------------------------------------------------------------
Disable . 4. 1. 1. 1. 1. . .2 . . 2. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 23
Open Lo . 3. 1. 1. 1. 1. . . . . . . . . . 1. 2. 2. 1. 1. 1. 1. 4. 3. 23
Search. . 4. 1. 1. 1. 1. . .2 . . 2. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 23
Spot. . . 4. 1. 1. 1. 1. . .2 . . 2. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 23
Diplo . . 4. 1. 1. 1. 1. . .2 . . 2. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 23
Balance . 4. 1. 1. 1. 1. . .1 . . 2. 2. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 23
Hide. . . 4. 1. 1. 1. 1. . . . . . . 2. 3. 2. 1. 1. 1. 1. 1. 1. 1. 1. 23
Move Si . 4. 1. 1. 1. 1. . . . . . . 3. 2. 2. 1. 1. 1. 1. 1. 1. 1. 1. 23
UMD . . . 4. 1. 1. 1. 1. . .2 . . 2. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 23
Heal. . . . .1 .1 .1 .1 .5. . .1. . . . ½. ½. 1. 1. 1½ 1½ 1½ 1½. . 1. 20
Jump. . . 4. . . . . . . . . . 6 . . . . . . . . . . . . . . . . . . .10
Haggle. . 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Tumble. . 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
. . . . .------------------------------------------------------------
. . . . .44 11 11 11 11. 5 11. 8 12 12 12 12 12 12 12 12 12 12 12 13
Feats
.1. . . . : Point Blank Shot
.3. . . . : Least Dragonmark: Healing
.6. . . . : Rapid Reload
.9. . . . : Precise Shot
12. . . . : Improved Critical: Ranged
15. . . . : Precision
18. . . . : Improved Precise Shot
12 Rogue. : Improved Evasion
15 Rogue. : Slippery Mind
18 Rogue. : Opportunist
.6 Deity. : Follower of: Silver Flame
Spells
- Cure Light Wounds (6), Nightshield (6), Obscuring Mist (6)
@ T - Sketched the start of your enhancements here.Some changes, since no Fighter/Kensai. You want to beeline to the Mech Core 6 (for Int to Damage w/ crossbow), the Tier IV Legshot & Fletching, and then balance the rest of Tier 4 & the Halfling self-healing line. Bank some points for Mech Tier V just before you hit Rogue 12, or respec something to get the points there - your best return on investment.
(And I'll fill the rest of this in later - no time atm, sorry) 
Enhancements (42 of 80 AP)
Mechanic (29 AP)- Arbalester, Tanglefoot, Targeting Sights
- Sharpshooter, Awareness II
- Sharpshooter, Improved Traps III, Wand and Scroll Mastery III, Skill Boost III
- Sharpshooter, Wracking Shot I
- Sharpshooter, Disable Construct I, Fletching III, Leg Shot
Halfling (13 AP)- Halfling Luck
- Jorasco Dragonmark Focus III, Acrobatic I, Cunning I
- Lesser Dragonmark of Healing, Break out the Leeches, Halfling Guile
- Greater Dragonmark of Healing, Halfling Guile