I know many highly analytic languages (Chinese, Vietnamese, Thai) are tonal languages. Are there similarly analytic or isolating languages that don't use tone the way those languages do? The closest I can find is Indonesian, but its verbs seem more synthetic than English, at least according to WALS.
The best example is probably Khmer. The difficulty is finding an isolating language at all, i.e. a language with absolutely no word-formation processes (where everything is syntax). In many linguistic theories, this is a spurious distinction (affixation is always syntactic). Today's no-affixing language was probably yesterday's lightly-affixing language, so in Khmer there are some sets of words of similar form and meaning that look like they have prefixes such as [ɗaəm] 'origin', [pʰɗaəm] 'to originate (trans.)', but these are not productive processes. There are compounds, but compounds are often treated as two words (not affixation) in typological theories that admit of a concept of "isolating". What is clear is that Khmer does not have tone. Another candidate is Kéo, said to be highly isolating, and not reported to have tone.
Yes, there are. You already mentioned WALS but you aren't aware of how to make use of it to answer the question: On the maps view you can combine the maps of different features. Here's a combined view of 26A "Prefixing vs. Suffixing in Inflectional Morphology" and 13A "Tone". The WALS sample contains 28 languages in the category "No tones / litte affixation":
Atayal Chamorro Canela Drehu Fijian Hawaiian Huastec Iaai Iban Koyra Chiini Khmer Kharia Khasi Makah Malagasy Maori Maranungku Rapanui Sedang Sanuma Taba Tagalog Tigak Tetun Ungarinjin Wari' Wolof Yapese
Of course, this sample needs to be reevaluated, but it is a good starter.