Just swallow it, preferably with distilled water not tap water as even small amounts of chlorine can destroy LSD.
While you can pick up traces of cocaine from bags, bank notes, and other people's hands it is unlikely that these traces could enter your bloodstream and be detected on a drug test.
One single use of cocaine will not make you an addict. Nor will two or three times. However, cocaine addiction is a gradual and insidious process. If there's availability and you can afford it, it is not difficult for regular recreational use to descend into habitual abuse. See our section on cocaine: addiction & tolerance for more information.
No.
It's possible that too high a dose of psilocybin could lead to a catatonic state but there is nothing in literature about black outs. How much are you taking? If you are taking relatively small amounts, it's likely your body is telling you something and you've made the right decision to stop. If you are taking large amounts (4 or 5 grams dried or more), it may be that your dose is just too high.
One time use of cocaine will not cause permanent brain damage or memory impairment. Even long term addicts suffering from cocaine psychosis and a host of negative physical effects fully recover if they can shake off the addiction.
Some resources that may be useful:
http://www.lindesmith.org/library/cocaine_index.html
https://www.erowid.org/chemicals/cocaine/cocaine.shtml
http://www.cedro-uva.org
Ketamine is hard to distinguish from cocaine. Generally it forms a much smoother fine-grained powder with less lumps or hard crystalline particles. It has a bitter taste and does not have a distinctive odor.
It is unlikely that an alcoholic test would be extended to cover LSD. LSD is rarely tested for in urine or blood test unless specifically requested. It is also difficult to detect, due to the microscopic amounts usually ingested.
None whatsoever. LSD is probably the least toxic of all recreational drugs, mainly because you take microscopic amounts of it (hundredths of a millionth of a gram).