Re: Sailing, safety, & size
That's a lot of questions. but for offshore work, days from shelter, I think it's more a question of weight than size.
An ultra-light 40-footer is less safe than a 25' wooden Vertue, in my view.
So personally I would want enough displacement that the boat's motion in a sea won't beat me to death. What is that number? 6000 lbs? 10,000?? The Albin Vega at 5000, has a good reputation offshore. I wouldn't want to go less than that. more like 7000 (Triton) or 9000 (Pearson 30 or similar). Sail area/displacement and ballast/displacement ratios would also matter to me.
Your NorSea 27, at 8000 with 3000 ballast, is much more rugged than the Vega, though likely not as fast.
Every boat is a compromise. You like yours. other like theirs. But yes, more size alone isn't necessarily safer, or (especially) easier to handle the larger sails and forces.