Dear Bleeding Heart Meester Nice Guy,
I too try to bring a little sunshine into the otherwise dim and cloudy world that is Costa Rica. Like so many gringos, I have the ability to instantly improve the lives of everyone with whom I come into contact.
1. The prostitutes: I know a couple guys who buy little gifts appropriate for either male or female offspring of the ladies. Most of these gals have young 'uns; a good option is coloring books and crayons. Stuffed animals take up too much suitcase space. Often, the way to a woman's heart is to gift her k*ds.
2. Beggars and fruit bars. I'd be curious to know the reaction of the junkies, glue sniffers, petty criminals, vagrants, alcoholics etc. when little Murray Sunshine drops a fruit snack on their semi-conscious bodies. Let me relate the experience of a now-absent CRT member, El Lamero. Last year, he brought the Burnt Boy a sandwich, taking the guy's word that he was hungry. The poor, horribly-burned teenager took one look at the sandwich...then threw it into the gutter. This will sound incredibly cruel: Don't feed the monkeys. Sonrisa, these folks are beyond craving food. Most are looking for the next fix. You want to make their glasses half-full in the midst of all their private horse manure? Find a tube of airplane glue, a bottle of guaro, a pack of cigarettes or another drug whose discussion is prohibited by Forum rules. They don't need or want your damn fruit bars, gringo.
3. Learning Spanish: Yes it's essential, but you're not doing the locals any favors by speaking their language. You're just doing what is respectful and respected, not to mention making your own life easier. Good idea, nonetheless.
Aside from giving fruit bars to the mendigos, I agree with your post wholeheartedly, but come on. Isn't this how all of us were raised? The Golden Rule and all that? I have tried to live that rule, not only because it's part of my religious upbringing but because it makes good sense. And hey, I also believe in karma and that everything you do comes back to you.
My own rules:
1. Treat the local folks with the same friendliness, patience and regard you'd give your neighbors back home...but even better.
2. Treat a whore like a lady. Never forget that with all her lying, manipulations, tactics, falseness, insincerity, chicanery and occasional criminality, she's not just a Sperm Waste Disposal Site. Hell, treat her like your sister, particularly if you're incestuous.
3. Kick the beggars only if you can get away with it (you usually can't). Give the mendigos no more that a 50 colones (ten cents) coin...then make 'em work for it. Throw it, don't hand it. These apes carry diseases.
4. Tip policemen generously, particularly the Policia Municipal in San Jose. A 5,000 colones bill is always appreciated, but you'll need several 10,000 colones notes to gift your way out of any real legal troubles (like getting caught kicking a beggar).
5. Useful Spanish phrases that show you're a loving, polite person:
Huay puta (from "hijo de puta") = I think your Mom is nice
Besame el culo = I want to get to know you better
Tengo ganas a culear su hermana = I would like to get to know your family.
Chyupeme hasta que me inchan los huevos = Are you hungry? I offer food.
Me gustan drogas. Tiene algunas a compartir? = Let's spend some social time together.
And yeah, I'm a half-full glass guy.
(The above post was mostly, not completely tongue-in-cheek, in case you missed it).
"Optimist and pessimist,
The difference is quite droll
The optimist sees the doughnut
The pessimist sees the hole."
- Ogden Nash
, but we have had MANY sessions together). Anyway, she looks very tired, said she hasn't had any business tonight, etc. I say "look, i just returned from my "semi-novia", i don't need any company (sexo), but if you want to go upstairs and sleep for a while for no money, thats fine". She said sure. We sleep, no sexo. Next morning while she is in the bathroom, i put 20,000 colones on top of her purse plus a couple candy bars from the mini-bar for her bambino's. We have breakfast at the Del Mar, i give her a hug, put her in a cab, and tell her to have a good day with her bambino's. Smart? 
Good karma? Damn right 