okay there are a lot in there that one can respond to.
I used to think the same and later I found out that is was all in my imagination. If you keep on concentrating on the negativity that 'might' exist then you are fuelling it and giving it a life of sorts.
Don't give it any more thought! Every thought has energy to it and one has to learn to become more responsible for each and every thought that pops into your head. A VEERRYY difficult task but it can be achieved.
So change your thinking asap! Happy vibes! loads and loads of happy vibs!! heehee
And i also don't believe in luck - but thats just me. I believe in only blessings and sometimes they can be a difficult one to learn but they are never bad or negative. the aim is to help you to learn something new about yourself or maybe get rid of some bad habits that you may have accumulated which can be physical or even spiritually.
With crystals, Gem is the expert here, but in my small amount of knowledge you could use crystals such as obsidian, smoky quartz, rose quartz, citrine, kynite, kunzite etcetcetec
Do some looking and poking around on the internet! Each stone has their little thing
Hope this helps a little.
Oh and this is not the only view point - its just mine
