Now, I was wondering about how I could improve on with respect to their impressions socially, since I am doing well currently in managing them with respect to personal wellbeing.

Perhaps I'm misinterpreting you, but I read the above to be asking, "How can I improve at x even though improving at x won't increase my wellbeing?"

Actuarial tables give him a roughly 2% chance of dying before the election.

Is there absolute utilitty maximisation in portfolio diversification or is that just a risk control mechanism?

It's purely for risk control, but most people are extremely loss averse and so do well to diversify.

Could I pick one random stock and put a whole lot of money in it? I suspect I may be commiting the law of large >numbers here (or the gambler's fallacy).

You could. It's a bet with positive expectation and a really risky one. But people do much dumber things with their money. Having said that, I'd recommend an index fund instead if you're plopping a whole lot of money in.

In digital markets with extremely quick liquidity like the stock exchange, Is investing based on macroeconomic factors and >megatrends foolhardy?

One shouldn't expect to systematically beat the market without privileged information. But even "trying to beat the market" (depending on what exactly that strategy entails) or doing what you describe is often better than what most people do in terms of actually growing their savings. Financial securities (especially stocks) have high enough long-run expected returns such that a "strategy" of routinely accidentally slightly overpaying for them and holding them still results in a lot more money than not investing at all.

Is it only sensible to invest when one has privellaged information including via analysis of public data at a level no one else >has done?

Not investing is far worse than shoving your money into random stocks and committing to reinvest all dividends for the next 50 years.

The "preferences version" of consequentialism is also what I prefer. I've never understood the (unfortunately much more common) "cosmic objective utility function" consequentialism which, among other things, doesn't account for nearly enough of the variability in preferences among different types of brains.

Here, it goes without saying that each of these positions is wrong.

I am under the impression that many in this community are consequentialist and that all consequentialists are moral nihilists by default in that they don't believe in the existence of inherent moral truths (moral truths that don't necessarily affect utility functions).

A college education is a terrible investment for the average person in today's economy. The money and (more importantly) the time spent would be much better utilized to obtain the same human capital and signaling power at a cheaper monetary cost and a faster rate than those at which universities are willing to provide.