seedboy, I don't know that there are 'best' annuals. But there is a very long list of great performers under a wide range of conditions. You'll need to evaluate the locations on your property for such factors as sunlight (how long and how much), soil conditions, and drainage. In Florida, you'll have plenty of options for the warm and hot months (spring and summer) as well as the cooler times (fall and winter). For example, this is not the time of year, in your location, to buy a flat of pansies. Though they may look wonderful at the garden center, they will only perform well for a very short time due to the heat. Fall is the time to plant them, for an all winter-long dispay. If you visit the Florida Forum, be sure to ask what their FAVORITE annuals are. I'm sure that people are likely to list such plants as marigolds, zinnias, gomphrena, Catharanthus roseus, portulaca, and lantana (which is a tender perennial but used as an annual.) And MANY more.

I don't grow many annuals, but nigella Miss Jekyll and papaver somniferum are always welcome. They both self sow regularly, sometimes I'll gather the seeds and toss them into a different area than they've chosen to sow themselves the previous year. Occasionally a few sunflowers, but I really don't have the space - which reminds me, I should pick up a pack seeds of the giant types for a neighbor who does have the space and I can enjoy those from my driveway :)

I think a single servicing is adequate and should protect the manufacturer's regular service warranty. I do mine in the late summer/early fall. Heat pump and 90% gas furnace. You could also do it in the spring/early summer. I personally think twice a year is overkill and probably a sales job for an additional service call. Unless the manufacturer's warranty specifically requires it, I would do annual service only.

Tile doesn't present itself as effectively against peb tec as it does against white plaster. For that reason, it isn't used on the steps as much. Pick a contrasting color if you do use it.