OK, so a few things. "Lo siten lohem chein" halachically means that we gain nothing from the deal, correct?
But who says it is for nothing in return?
The entire point here is that I get a gift of sobriety and peace of mind by praying for the people I am lusting after, mad at, want to strangle, or am afraid of. And I get it. So I am benefitting from my gift. If they also benefit, then who is to cry? Hashem is giving them life and plenty brocha (indirectly), who am I to want them to have no brocha of any kind? And if, as you say, "but it has been doing wonders for me lately" then I guess you are using these human b'riyos of Hashem for your own benefit just as He wants you to.
But it needs to be sincere. And you already know that it works...if we let it.
And while I am on the subject of "b'riyos", don't you also mean goyim when you say to Him "Boruch merachem al hab'riyos" and "Yismach Hashem b'ma'asov" every morning? OK, so maybe your particular hashkofa (and there are differences in rishonim and acharonim on this) prefers to see Hashem's Chessed and nachas from the goyim specifically in spiritual matters, not in any phyiscial brocha or tov. For example, the goyim all coming to their own tachlis as our perfected chitzoniyus (as in "v'noharu eilov kol hagoyim" in the time of moshiach, b"b). So, what's wrong with davening for a goy's spiritual development into a man or woman who recognizes and believes in his or her Creator as the Nosein haTorah? To whine about chillul Hashem among goyim "Oy, what a shanda that it should be in the paper that Rabbi so-and-so molested children!" - implies that it matters what the goyim say and think about Hashem and His people! Why does it matter!? Is it for our kavod? Surely not. It must be for Hashem's kavod...but then why does it matter what is going on with a goy's faith in Hashem and His Torah?
Ella what - clearly Hashem wants the spiritual growth of goyim, too. It is childish and silly to retreat into some blind and dark mishega'as that "all Hashem really considers good for goyim le'osid lavo is for "all those evil goyim to see their folly (Ha!) and be punished!" Yeah, yeah, they deserve something...but G-d is b a lot bigger than that. Their hakorah is what He wants. He 'wanted' it from the mitzrim by yam suf and He will want it b'acharis hayomim, too, from the bad people among the goyim.
But it is clear that davening for a goy to be granted true spiritual inspiration from Hashem to live rightly as a goy is a great mitzvah and well in line with the tikkun of the future. So why not ask Him for it for them today? Especially since you and I end up laughing all the way to sobriety, sanity, and peace of mind!
And, as generally when I daven for myself it is only for spiritual and mental help (see the first brocha in Sh"E, and also the 11th step which we addicts try hard to put into action), when I daven for a woman I am lusting after 99% of my tefillah is (and always has been) for "their spiritual connection with You, Tatty. Please, please help her know the truth of Your Beauty and Your Goodness, that everything valuable in their lives only comes from You, and not be fooled by false people who will use them!" I sincerely hope that nobody is used and trashed as these women most often, are. It is tragic, even if they seem to bring it on themselves - it is a sick, painful and tragic thing, to live out this huge gift of life in a trash can of depravity and confusion about what has real value and what is just a show. It really is.
Final point, be"H. And as painful as it is, I must write this; and I am not criticizing anyone in particluar, least of all any of you c'v. I love you guys, every one. I am just illustrating a point. Imagine: If it was a regular weekday, and you witnessed a man apparently abduct a 10 year old goyishe boy into his car, what would you do? Would you not care? Would you not try like crazy to save or help that boy? Would you not care of the pain of his parents? Of his horror before possible death? Or are the only real emotions Jewish ones? Are we turned into animals now, who see no pain in the suffering of those who are not in our family? Rachmonim - is a sign that we are Jews. A yid who says that "Rachmonim" only applies to Jewish people who are suffering, is nothing but a sheigetz, to me. And I believe that the Sh'chinah hak'dosha would 'run' from such a person k'borei'ach min ha'eish.
Everybody has suffering in life, and everybody dies. And dying is not pretty, at all. Plenty of our suffering is the result of our poor choices in life. We all need protection from bad influences, from stupid decisions, and from having sick thinking that unecessarily paints our lives in ways that make life seem a horrible thing. What harm is there in having rachmonus on the goy I am lusting after - for the needless suffering he or she might feel? What is wrong about me davening for Hashem to spare this person from unecessary suffering and pain due to deyos kozvos, sick thinking, and terrible mistakes in life?
OK, enough out of me. Sorry it was a megillah.