I'm sorry dude, but this is so wrong. Dealing in absolutes, you will always be wrong. There are A FEW products that do move through the food chain like that, but any new chemistry and most old ones that are still registered do not do this.

I appreciate that you're looking out for the environment, but these are half truths.

Sincerely, Golf Course Superintendent and licensed Master Applicator.

They kind of are, but not in the way we consider the term. Broad spectrum or non-selective on a label means kills/has effect on everything or many of that type (insects or grasses). Most insecticides, especially residentially labeled products, are selective. Spectracide kills ants, Acelepryn (which we can't get in Maine but should be able to), kills weevils, grubs/the beetles they grow into, and cutworms/sodwebworms. Insecticides and fungicides all have specialties

Most products are also only effective in certain life cycles. If you water down a grub treatment, it's not going to work on surface feeding insects. Depending on what you can get, it also likely isn't going to kill beetles anyway. Products like Provaunt that inhibit the growth of eggs only work on egg laying periods.

Insecticides may have other things written on the table as effective, but that usually a low bar. University of Kentucky has good trials of herbicides and Penn State has been doing some good stuff with White Grub trials.

Not quite accurate on grub treatments. Insecticides aren't broad spectrum like Roundup. And the stuff that's on the market for commercial and residential use is safe when it's watered in properly.

You can (probably shouldn't yet depending on your level of frost) do any type of thatching now, but wait on your premergent weed product until May. Grub products should go out around July.

This is still early for thatching IMO, as there's still a lot of frost in the ground (at least in downeast there is). Working frozen/semi frozen turf can and will shear off your roots at the frost line when the top inch or so is soft. Then you're negating anything you do.

Any and all seeding and aeration NEED to be done before you get your premergent down, as seed won't establish in the early weeks after pre-em. Aeration creates passages for weeds to grow through the "blanket" that pre-em creates.

Be careful following what the landscapers do, as some are looking to do pre-em early so they get to come around and charge you to attempt to kill 7 tiller crabgrass with the pea shooter arsenal they have.