There are some words (handset, kablooie) that are clearly unfit for a story set during the reign of Queen Elizabeth I (1533 - 1603). But there are lots more that are ambiguous.
I've run a few of the words I'm most worried about through the OED to see if my fears are groundless or justified. Any that have lacked a definitive answer from the OED, I've used a concordance of Shakespeare as a back-up. There are some real surprises in the list - chuckle fercrissakes. Language is a constant torment and a lesson.
If the words were in use before 1608 I've deemed them safe. Later than that and they are ruled out. This has been a really useful exercise and lots of fun, its made me think about how I use some words and will make me think of different ways to say some things.
concotion (1531 - but only of digestion. 1851 to describe a mixture)
laboratory (1592 - in Dee's own work!)
spindrift (1614 - of spray)
conversation (1340 - to mean living among others. 1830 - specifically as talk)
rug (1547 - a coarse woollen cloth)
nightgown (1475 - a loose gown worn over night clothes)