No. The free ranks of a skill granted by certain species, such as the Sollen's free rank of Engineer and Extra Mods, do not make buying additional ranks of that skill cost more. The ranks granted by your Species are treated as “bonus ranks” after character point costs are determined.
It is possible for a character to kill themselves, via delivering a LETHAL call to one of their own unprotected locations (a character can choose to be Unresisting to their own attacks if they wish). This will start their Death Count, during which it is still possible for other characters to save them.
No. As described on the Calls & Effects page, Game Calls are out-of-character. They are not audible, and are only noticeable via their effects in-game - someone falling over, etc. Calls that come from an attack will be fairly obvious as to their source, but calls from special powers or psionics less so. Characters who are familiar with psionic powers might be able to spot the signs of them being used, such as a character being at the epicentre of a bunch of other characters suddenly succumbing to anger, or a character staring intently at another for about 30 seconds, but these are in-character inferences rather than reacting to an out-of-character Call.
Suggestions and similar effects are roleplay effects, which alter how your roleplay your character somewhat. MESMERIZE is a Game Call, which has specific rules that you must respond to in a specific way. Calls take precedence over other effects. So if you have a Triggered Suggestion to do a pirouette when you are Mesmerized, you would not respond to it until the Mesmerize broke.
You cannot cross the OOC site boundary In-Character. Event sites are shielded against entry and exit a short distance from the OOC site boundary. The only way to leave the IC area In-character is via a Gateway, Elysian Nexus Tree portal or similar.
While you don't need a full crew of 5/6, it certainly makes things easier. The standard hire starship from the Spacer Collective will have 5 stations - Helm, Weapons, Engineering, Science and Relay (plus the Captain). You can still embark on missions with fewer crew, but it will be more difficult to switch between them and get everything done. As a minimum, you will probably need someone on Helm and someone on Engineering to get about, but actually finding things and shooting things will be much harder. Remember that anyone can use every station to a basic level - the spaceflight skills just grant bonuses to your ship.
However, you don't have to fill a ship crew entirely from your own group. You can ask for help from other characters, and some might be willing to hire their skills out to help you - maybe for a flat fee, maybe for a cut of the profits.