I am not an expert since this is my first year, but I live in S. Nev and have temp in the 100's here. So I seem to have better luck with starting most of my seeds inside using one of those seed starter flats with a clear cover. As soon as they pop up, they are transferred to small pot (plastic or styrofoam cup)which is labeled and dated and placed in a sunny window. Within a few days, most will then go outside into a mostly shady spot and then will be moved to a sunnier location when the second set of leaves are fully formed. I tried germinating directly in the bed and although several came up quickly, they seemed to get eaten by the insects too quickly and few remain.

Google temperature seed germination. The following article has a chart that shows % of seeds germinated at different temperatures. In parenthesis () is how many days it took to achieve that % of germination.
http://tomclothier.hort.net/page11.html

There are not too many things that cannot be transplanted, most do well, especially if you take care not to disturb the roots. You will definitely have to make sure the small pots do not get dried out. Also, harden off the seedlings before transplanting.