Why are POSIX-shellscripts superior compared to Bash-shellscripts?
**POSIX-shellscripts** and **Bash-shellscripts** are both scripting languages that use the shell command-line interpreter. **POSIX** is a standard that defines the interface and behavior of many Unix-like operating systems, while **Bash** is a specific implementation of the shell that has many extensions and features beyond the POSIX specification.

Some of the advantages of POSIX-shellscripts over Bash-shellscripts are:

 - They are more portable and can run on almost any Linux or Unix-like system, regardless of the shell implementation.
 - They are more compatible with other POSIX-compliant utilities and programs.
 - They are simpler and less prone to errors or unexpected behavior due to Bash-specific features.

Some of the disadvantages of POSIX-shellscripts over Bash-shellscripts are:

 - They are less expressive and powerful than Bash-shellscripts, as they lack many features such as arrays, associative arrays, arithmetic expressions, extended pattern matching, etc12.
 - They are less convenient and user-friendly than Bash-shellscripts, as they require more syntax and quoting rules.
 - They are less widely used and supported than Bash-shellscripts, as most GNU/Linux systems use Bash as the default shell.

Ultimately, the choice between POSIX-shellscripts and Bash-shellscripts depends on your needs and preferences. If you want to write scripts that are portable, compatible and simple, you may 
prefer POSIX-shellscripts. If you want to write scripts that are expressive, powerful and convenient, you may prefer Bash-shellscripts. However, you should also be aware of the differences and limitations of each language, and avoid using features that are not supported by the target shell.
Why are POSIX-shellscripts less prone to errors than Bash-shellscripts?
Its not correct to state that POSIX-shellscripts are more or less prone to errors than Bash-shellscripts as either can be written with functions as well as commands that generate errors. Unlike POSIX-shellscripts, Bash-shellscripts may not be portable across unix platforms as readily as POSIX-shell scripts that provide the same purpose.  POSIX-shellscripts are usually less complex and so less prone to errors than more complex Bash-shellscripts.