Well, many spells on this site can be classified into the categories of Real and Fake. Most Fantasy and Trick spells are fake. But there are also many spells in many different categories of this site that are real and fake. It can be quite tricky to tell which is which.
Generally, you'd want to stray away from most spells on the site. If you do wish to cast a spell by someone on this site, check their site history to see whether or not they are 'Fluffy' or fake, or they actually know what they are talking about. You may also want to judge a spell using common sense, intelligence, and maturity. Anyone on this site can post spells under certain circumstances, so just be careful about what spell you're casting and who it's created by.
You may also want to consider an alternative; making your own spells. They are more likely to work because they are created by you. You know what you want to happen, and you know what you have at hand. They also have the intention in them due to you writing them with the intention in mind. So if you, like many others on this site, do not trust the spells then create your own.
I completely agree, the spells will be strong and have a better chance of working if created by the one who is going to cast it. It is their own energy going into the creation, preparation, and casting of the spell, therefor making it stronger. Cast someone else's spell does not allow for your energy to be what is driving it so it has less of a chance (in my eyes), the purpose for which it was created may not have been the same or (other then the fact of the fake ones on here) they may not have put a whole lot of energy into it. Some who may not take is as seriously as others may have just sat down and made one up just to post one and even if they were serious it may not have been thought out or truly had a purpose(just words thrown together last minute).
I always go with my own but I will go to the spells and search for what I need and look to help with ideas (on starting or wording) sometimes if I am stumped.
Hope this Helps, Sorry I got a little rambly. I'm tired and it is 6 am here. I have been up all night with a migraine. But don't feel bad, most of the time they do not involve pain just everything else like sensitivity to light, etc.. and I am a night owl so to speak. Just not normally this late. :)
Feel free to use the site's spell. Be careful though.
Learn what we can achieve by developing our spirituality and working with energies. We can psychic defense, achieve emotional states and affect feelings (which are associated with energy, thus they are spiritual), get a positive / negative attitude, or simply direct energies (feelings as well) upon a specific desire / intent.
What we can't achieve is a physical change, since things that belong to the spiritual field will always belong to it. Things that belong to the physical field will always belong to it as well. Physical changes talks about transformation, physical changes (appearance), etc.
Use your logic, maturity and personal experience with the craft and you're fine.