In a way, seed is cheap. Do both, keep notes, and the indoor starts are backup. It's most likely all-win.

If the heat concerns you a lot, strew straw, or rig some midday shade. Sheets, shade cloth, milk crates, a shadow from a bucket, all sorts of things work.

The primary reason for starting seeds indoors is to give those of us with shorter growing seasons time to grow some plants that need a longer growing season then we normally have, or to get frost tender plants up and growing so the late frosts do not kill them off. The kale, onion, broccoli, lettuce, and spinach are all cool season plants and are frost hardy and they can be direct seeded even up here in the north. But they also struggle in soils that are above about 70 degrees. If you have a place that is cooler then the outside soil starting those there might be better.
The others are warm season growers that like the warmer soils and would do much better being direct sown.

It is time to direct-seed collards and other brassicas for central florida. Definitely not for lettuce. Brassica seed likes to germinate in warm soil and then experience cooling temps as the plant matures, which is why it is often sown in june/july in more northern climates and now in the deep south. Lettuce is not an easy crop for florida at any time, however for direct-seed do so in mid-october.

It is now a bit late to start tomato from seed for central florida - better to buy plants in a few weeks.

The suggestion to hedge your bets by direct-seeding and start in flats is a good one.