At arraignment, how much is bail usually set for? Worst case and best case scenario

There is no way of knowing the amount of bail. What your friend needs is a good criminal attorney.

Bail is not just about the charges, it's about the record, the potential flight risk, his incone, and even the mood of the magisterial district judge. If a missed hearing was his fault, that would be a factor in favor of higher bail

There is no way anybody could know this. A person can be released with no bail to remand, depending on the criminal record, any prior warrants, the amount of time they are facing if convicted etc.

Nobody can tell you what the MDJ will set his bail at. This decision is in the Judge's hands. The Judge will assess the following: the Defendant's ties to the community; the probability of the Defendant attending all future court appearances; the Defendant's prior criminal record; and any other information the MDJ deems to be relevant. Once the MDJ has "assessed" the Defendant, the Judge will set bail. He essentially has three options: Released on own recognizance (ROR); Unsecured; and Secured. ROR means your word is your bond. You will not be required to post any money to be released. Unsecured means you will be released on a monetary figure, yet your signature will suffice and so long as you attend each subsequent hearing, you will not be required to pay. Secured means you will need to "post" either a percentage or a flat amount. Bail is an important aspect of the criminal process. If not taken seriously, the Defendant could be sitting in jail until the case is disposed of.