Gear wise - I noticed you're still in a lot of blue gear (did you log out in pvp gear after doing bg's, or is that what you healed the raid in?), which means you're still pretty low on Spirit (You have almost half of what I have, actually). Holy Priest's mana regen is highly dependent on how much Spirit we have. Until you get better gear, your mana regen is going to be pretty abysmal in a raiding environment, where you're casting a lot of relatively high cost spells. As a personal preference, I like to keep my haste around 1000, but you don't even really need to go that high (I can never remember what the haste break point is. I think 12.5% raid buffed? Correct me if I'm wrong). After that I stack Mastery. But make sure you have Spirit on ALL of your items.
Also, never raid in pvp gear if you can help it...
Talent wise - You really don't need Blessed Resilience. If you're having mana issues, I recommend moving that point into Veiled Shadows in the Shadow Tree. See if you can squeeze another point into that as well (Probably from Darkness). This will allow you to use your Shadowfiend more often.
Glyph wise - Personally, I prefer having the Lightwell Glyph over Renew, because I don't find myself casting renew that often. This is especially true for LFR, where a majority of the healing going out is probably being taken care of before HoT's have a chance to do what they do best.
But like others have said, it's LFR. LFR is practically a healing snipefest. The healers with higher gear are always going to out perform you, the healers who have their aoe heals going nonstop (Healing Rain, Sanct, Efflo, lolpallyspam (I tease)) are generally going to out heal you. What matters the most, in my opinion, is the over-healing that's being done. When you're healing, try to predict when damage is going to happen, drop your sanct a few seconds before that, and then start your PoH and CoH once they start taking damage.
Edited by Akaeya on 3/21/2012 6:26 PM PDT