43 still gives you about 20 more years than most people to do something other than earning money to spend! Imagine what you'll get to do with that kind of time.
I love hearing from other people who have a similar plan.
And of course I'll suggest you could be independent sooner if you reduce some spending. ;) But that's your tradeoff to consider.
Here are some resources that explain why to do this and how:
https://www.reddit.com/r/personalfinance/wiki/investing
http://www.mrmoneymustache.com/2011/05/18/how-to-make-money-...
There are endless ways to diversify. For example, my portfolio is "diversified" across all stocks. But the entire stock market goes up and down, so some people diversify by putting a percentage of their savings in something else, like bonds or money market funds. These tend to have lower historical average returns than the stock market, but they won't necessarily go up and down at the same time so your savings will not fluctuate as much.
I haven't looked into paying less taxes, aside from maxing my 401k.
Part of my interest in them is that the world's population is stagnant and will begin to decline soon -- creating an environment in which growth will be impossible, quality will prevail over quantity (goodbye, Caterpillar and General Electric!), and rent-seeking will be much more successful than profit-seeking.