Regarding the limitation of 100 records (or 8000 records when scripting), it looks like there is a little hidden gem built in here.
According to this support page, if you use an array of linked records (from a linked record field) as your input, you also get the increased 8,000 record limit! 
Is there an upper limit related to the number of items that can be looped through in an input list? Yes, there is a limit of 8000 items per input list. This limit might be reached in automations that contain input lists that reference arrays from scripting outputs but can also apply to automations that use a linked record or user field as an input list source. Automations using the Find records action as an input list source are already limited to 100 records per action, which means that it will not exceed this limit.