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I have read the sticky post about blossom drop, but not sure about the cause of my first blossoms bending, then breaking off my tomato plants. The plants are young, only in the ground about 3 weeks, I'm hoping this will go away, any ideas?

P.S They bend about 1/4 inch behind te blossom, then break.

That is normal for flowers that abort for whatever reason. Often for unsuccessful pollination.

So I assume the plant still has a decent chance of producing some fruit?

I get more of it happening in mid summer, about the time I try to make crosses. If the crosses don't take the flower breakes off. So I assume that high temps (and maybe humidity) have something to do with it.

Crosses? Not sure what that means?

Trying to cross one variety with another to produce a different type, that is fertilizing one flower with pollen from the other variety.

The point in there is just that if the flower is not going to set fruit, it breaks off like that. All the things in the blossom drop sticky you read apply... all those are reasons why the flower will drop off instead of setting fruit.

Here's from that sticky:

Blossom drop is a reaction to stress -- the plant drops the blossoms to focus on survival. The stress can be from a variety of causes-- temperatures too low or too high, humidity too low or too high, too much or too little nitrogen, lack of water. Early in the season blossom drop often relates to night time temps going below 55.

So, I don't know what temps you are having in FLA right now, whether it could still be too hot and humid for it or whether you are having night time temps below 55 (here we are having night time temps around 20!). But any of those things can lead to blossom drop as you are seeing.

It is a problem with the conditions, not the plant, so if the conditions improve, the plant will start setting fruit.

Wow, What a great surprise, watering the toms this morning and found a few small fruit growing!!
The crossing thing, Is it a problem to plant different kinds of toms in the same bed? I have six plants going in a 7 x 5 ft area.

Garden size has no impact on incidence of cross pollination because multiple bees hit pretty much all plants/flowers in a somewhat random manner. Bees scent mark flowers they have just visited so whole plants may be skipped over by the next bee, and the situation changes 15 minutes later as the scent wears off. The bees are "milking' the flowers for pollen to pack into egg chambers and are covered to some extent with pollen from every plant they have visited. You need to grow big plots of same variety plants separated by a pretty long distance (hundreds of yards) to keep the bees honest.

The tomato flower is designd to promote self fertilization so even with a bee mollesting it there will be over 50% self pollination. 20% is average during high bee activity at my house with a range from 40-0% for any one fruit.

Cross pollination does not affect the fruit on the plant, only the seeds. If you are saving seeds for yourself it's not that big of a deal if 5%-20% are crossed because you will recognize them and have a bank of true seeds in storage. The problem comes when you trade with someone who doesn't know the characteristics of a variety, and only grows one or two plants and then gets an off-type from the cross, saves seeds and passes them on. You often see the result discussed as "unstable varieties" or "spontaneious mutations" purchased from seed venders.