test management Questions

So, I'm writing automation tests for a huge web platform. We have page objects folder with files for each web page which contain a great amount of selectors used in tests. Also, tests pertaining to one of the component/functionality are all grouped in one file. 

The main question is whether the functions used by multiple tests (and some will have assertions in them) should be written:

1. Functions w/o assertions in page object and those w/ assertions in helper file for that component/functionality

2. All functions in helper file

3. Functions w/o assertions in page object and write the rest of the commands with assertions in the specific tests even though they may repeat and make the file with tests huge.

Testing is done in javasctipt(more recent: typescript), selenium webdriver, protractor, jasmine.

I really hope someone can solve this conundrum since nobody in my office has enough experience to help me. Thank you!

p.s. Should we group tests in one file? or write wvery test in a separate one?  

I was just wondering if anyone decided to make the switch and, if yes, how did that go? 

Any feedback? 

Does anyone here have any experience or knowledge of performing acceptance testing on automated conveyor systems utilised for the sortation of items.

This is a mixture of software and interfaces with moving machinery and integrating into data systems 

For example conveyor or materials handling conveyors used in the managment and distribution of luggage around a large airport 

I am looking to understand how you defined the scope of test and the framework adopted with the possibility of benchmarking the activities you have performed.

Any advice would be greatly appreciated.

I an 5 years experienced Automation tester(Selenium Webdrver) and have completed ISTQB FL. What are the other certifications I take up related to Agile/Automation/IoT/DevOps/Mobile Testing?