Let's see.
On the face of it, +4 Str alone (unbalanced) is worth at least LA +1, thanks to the attack bonus. +2 Dex, +4 Con: wow. +2 Int, +4 Cha, +4 Wis: Wow wow wow.
Outsider type: solid gold. Immunities to a bunch of stuff. Yay!
The energy resistances are pretty good, but don't scale with level.
Darkvision and
daylight (at will) are okay, nothing to write home about.
Disease immunity is campaign-dependent.
Natural Armor +1: whatever.
Wings: good at low level, but
great at high level. Natural flight is fantastic when magical flight is assumed and
anti-magic field becomes an issue.
Smite Evil: Nice for the extra daily use. Can be really nice if you allow feats to grant extra smitings, or if the PC could already smite (and this just grants another daily use).
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The stat boosts alone make me pause at allowing this for a mere LA +2. The original template's spell-like abilities are misleading, since you'll always be four HD behind the "appropriate" effects on the chart -- at ECL 5, you'll get the 1 HD effects, and you won't get the 7 HD effect until ECL 11. So the value of the SLAs should be pretty low.
The template's SR is pretty weak, too. 10 + HD (when HD = ECL -4) is pathetic. Foes with a caster level equal to your HD will penetrate this 50% of the time (if they don't invest in spell penetration), and they are four CR below your ECL! Foes with a caster level equal to your ECL will penetrate your SR at least 70% of the time. So IMHO the SR isn't worth much.
- - -
So, IMHO you're giving too much for too little, even granting that stat boosts are worth (relatively) less for such high point-buy PCs.
Here's what I'd allow for LA +2:
- Type remains the same. In my game, you'd gain the (Good) descriptor, since I prefer to use descriptors rather than alignments to determine the effects of alignment-dependent spells.
- Feathered wings: fly speed 60 ft. (good)
- +2 Str, +2 Dex, +2 Con, +2 Int, +2 Wis, +2 Cha: as a half-celestial, you're better at everything.
- Darkvision 60 ft.
- Daylight (Sp) at will
- Natural Armor +1
- Energy resistance 10 (acid, cold, electricity)
- Immunity to disease, +4 to Fort saves vs. Poison
Cheers, -- N