You can attempt to withdraw the plea if you wish.
Regulations on plea withdrawal differ greatly from state to state. You should consult your attorney.
You need to talk to a lawyer.
A "plea bargain".
No. No state permits anyone ruled mentally incompetent to own or possess a firearm.
No the weapon first has to be found, then only can a person be convicted.
You can be CHARGED with it. However, the cops will most likely run routine license checks on the car, and will figure out whose car it actually is, and remove that charge. I hope for your sake that the person who's car it was gave you permission to use their car, or you will get a car theft charge as well ^^
Then I would imagine that there would be several reasons to hold the person involved. Unless the firearm was obtained while the felon was in a state of diminished capacity I would expect the possession charge to progress normally. The person had to have possession of the firearm to attempt suicide with it.
Same as any other person- yes, if they post their bond. You need to talk to a lawyer and a bail bondsman.
Yes, a jury decides if a person is guilty or not guilty.
No, they commonly aren't found guilty. However, if there is a case of homicide, the person in possession of the firearm and of course all possible suspects/accomplices/etc. will be questioned.
The court does not assume that you are necessarily guilty just because you plead guilty; there are many cases of innocent people who plead guilty, usually because of some mental illness. A delusional person may believe that he or she is guilty of something that he or she did not actually do. So, the case is still investigated, the evidence is still examined, and the person who pleaded guilty might still be acquitted. However, a guilty plea does constitute some degree of evidence, and it may lead to a guilty verdict, even for a person who is actually innocent. It depends upon what other evidence is available, and upon the care with which the court is handling the trial. It is unfortunately the case that sometimes the police and the prosecutor are just happy to convict someone, whether that person is guilty or not. It counts as a successful prosecution, that someone is found guilty.
There is no sentence for a search warrant. If, during the search, evidence of a crime is found, a criminal charge may be filed. The sentence, if a person is found guilty of the criminal charge, will depend upon what the criminal charge is.
If you have received a suspended sentence, you may still have restrictions on owning or possessing a firearm. It is important to check with local laws and regulations regarding firearm ownership and any restrictions that may apply to individuals with a suspended sentence.