To satisfy V.2 of the Immigration Rules you need to demonstrate that you are a genuine visitor who will leave the UK at the end of your visit.
To do that, you need to provide evidence that you have a compelling reason to return to your country of residence. Looking at the list of reasons you mention:
Academic Commitment: Pursuing a degree. Typically this would be likely to be viewed as a positive, depending on the nature of your studies. An online course wouldn’t carry any weight, for example; conversely being say six months away from completing a 3 or 4 year degree at a well-known university would be a (strong) plus.
Entrepreneurial Obligations: Developing a start-up with a two-year grant commitment.
May be a positive factor but it would depend on eg how far you’ve got with the project, its size, how much of your own money is tied up in it etc. It wouldn’t count for much if you could continue developing it remotely and/ or have already received / spent all the grant money.
Training Requirement: Enrolled in mandatory follow-up training. No idea what this means but doesn’t sound like it would matter much if you didn’t return.
Employment: Currently employed. This is a positive, although length / type of employment and salary may affect how it is perceived by the decision-maker.
Research Engagement: Participating in a local research project.
Shows you’re involved in the local community but on the face of it doesn’t sound like something that couldn’t manage without you should you decide to remain in the UK illegally.
Family Ties: Living with immediate family.
Useless unless they are financially dependent on you and need your physical presence.
As @jcaron commented, evidence includes pay slips, bank statements, certificates of incorporation, business accounts, certificates of enrolment, etc. Each type of occupation will have associated evidence, so with all those occupations, that would indeed result in a pile of documents.
You might find the graphic in this answer helpful in understanding how a visa application is likely to be risk-assessed. It relates to a Schengen visa but the basic principles also apply to the UK. If your profile is ‘young, unmarried, risky nationality, no/little previous travel history’ you’re likely going to get a refusal no matter how much paperwork you give them.
