My take is there is not much demand for the trending real estate, I've seen days go by without much new stuff on trending.

If there were no demand then sincere and success-minded Steemians such as yourself and @aggroed wouldn't be redirecting the reward pool simply for the purposes of visiblity!

The time it takes for Trending to refresh is a function of both the parameter of the algorithm (which is why Hot refreshes faster), as well as the amount of votes, largely paid votes, piled onto the posts. With less paid votes being misused for this purpose, it will cycle faster.

But to the extent it doesn't cycle that fast, it means there are even fewer slots. Now you have to argue that one's content being pushed up there is among the most worthy 3-4 posts on the entire platform in a day (or top 5-10 for the first couple of pages). Occasionally, this may be true. Often it is not.

If new content wants to appear in that real estate space then it will have to outbid what is there, which is healthy, creates a demand for SP or demand for Steem to purchase votes

We will have to simply agree to disagree. Paid voting is not healthy for Steem. It undermines curation and the value of Steem as a mechanism to give rewards to worthy contributions.

As I said, we agree there is a role for some promotion, but treating the biggest reward payouts as being a matter of "outbidding" is unhealthy.

We didn't double curation and introduce free downvores for no reason (and further introduce a non-linear curve which has a heavy cost on smaller reward-earners and communities, but necessary in order for EIP to have a chance to work). That would all be completely unnecessary if we were happy with the paid voting model and 'outbidding'. We did it specially to shift the emphasis away from vote selling and toward curation.

The dichotamy of vote selling vs. begging is a false one. I would suggest that you redirect your considerable entrepreneurial skills away from pure vote selling and toward creating vehicles for people to get their content in front of curators and vehicles for promotion that don't also involve redirecting rewards in an unintended and unhealthy manner (for example, perhaps we could have an ad-network where people can pay for visiblity across Steem-related UIs, just a quick brainstorm).