Guardrails are there to help prevent falls from the working platform by creating collective edge protection around the user. They are one of the key safety features that make scaffold towers safer than improvised access methods. Guardrails should always be fitted in line with the manufacturer instructions and never removed simply to make access feel quicker or easier.
Toeboards are fitted around the edge of a working platform to help stop tools, materials, and debris from being kicked or sliding off. They form part of the tower's collective safety measures alongside guardrails and proper access. On many jobs, toeboards are an important detail because they reduce the risk to people working or walking below.
No. You should never climb the outside of a scaffold tower, because it increases the risk of falling and can destabilise the structure. Always use the built-in internal access method provided for that tower system. Proper access is a basic part of safe tower use and should never be replaced with a quicker but riskier shortcut.