Speculation or Reasonably Logical Connection?

Considering my bad time management and difficulty prioritizing over the last year or so, I think I've made some good progress on my bachelor's project. I've done more research than needed for the level of academic rigor required. With some good advice from a past teacher, I’ve started an early morning writing habit. Work is getting done.

Before this point, I had focused on developing my thoughts and molding the source material into usable form. Trouble now arises when I try to fill conceptual empty spaces between facts and coherent, cohesive conclusions. Each time I make this kind of attempt, I ask whether the new premise comes from utter speculation or whether I've made a reasonably, logical connection.

I don't know of any hard and fast rule for making this determination. In the past, I would research my ass off to find answers. I would follow three directions for my research:

1. Primary and secondary sources directly addressing the historical events and people
2. Materials regarding the phenomena at hand (ie utopianism)
3. From Wikipedia to anywhere on the Internet to the physical library, whatever topic came to mind:
   
   • Social psychology
   • Cognitive science
   • Social/moral/political philosophy
   • Sociology
   • Anthropology
   • Economics
   • Cultural studies
   • Religion
   • Spirituality
   • Literary criticism
   • Literary theory
   • and the list goes on and on ad infinitum

I got some mileage through this approach. However, it got exhausting and results entered diminishing returns, probably about a year ago.

At the point of diminishing returns, I get less out of research the more work I put into it. It takes time to develop ideas and grind out demonstrable work, even if just brainstorming or drafting. Just sitting down at my creative desk with pen and paper at this point would more than likely just frustrate and throw me into a dead end.

At my day job, I have a good opportunity to let my brain free reign to ruminate and develop ideas to say sane. Otherwise I'd just focus on angsty, personal unproductive thoughts.

Brainstorming ideas is fun. My brain, at least, has an excellent talent for it. A lot of great results come from my brainstorming, and much of it has potential, too. These prospects get even better when they have a sound basis.

The problem arrives at this point:

• Are the ideas I'm coming up with pure speculation or a reasonably logical connection?
• Am I pulling an idea out of my ass that just sounds good or would be fun to write about?
• Does my idea have grounding in history and theory, or am I just enamored with a theory that I want to force onto history?
• Am I just using the first idea that comes to mind, or do I have an idea that will stand some test of academic rigor?
• How do you test the academic rigor of these kinds of ideas?

For now, I'm testing these types of ideas by asking

1. Is the idea simple and elegant, does it beg the minimum number of questions compared to other ideas and
   
2. Does the idea lend coherence and cohesiveness to the larger argument and project?

This approach serves my purposes for now. Is it something that can serve your purpose or do have your own approach?