As a ragtime aficionado and player, but not a musicologist, I have a narrow interest, which gives me some insight. My main sources for this information are from Edward Berlin's books "Ragtime: A Musical and Cultural History" and "King of Ragtime: Scott Joplin and His Era", plus whatever rabbit holes that led me down.

The 1893 World Columbian exposition (Chicago World's Fair) seems to have been considered a watershed moment for the evolution of this American style of music, as attested by contemporary sources. One of the features of this fair, beyond the music, was the creation of world "villages" including a Dahomean (modern-day Benin) village including Dahomean natives, a picture of which you can see on the page I linked.

European composers were paying attention to evolving American styles. In 1895, Antonin Dvorak in a Harper's article, advises "American composers to build a national style on the music of Negroes and Indians" [1].

Ragtime's first published piece is arguably W. H. Krell's "Mississippi Rag" (1897). Joplin's first rag is published in 1899 ("Original Rags). He moves to St. Louis in 1901. Alfred Ernst, a German, who conducted the St. Louis Choral Symphony, was taken with Joplin and subsequently (possibly) performed Joplin's "Maple Leaf Rag" and Joplin/Marshall's "Swipesy Cake Walk" on a trip to Germany.

In 1901, Joplin himself advertised in the paper that he was to perform a concert in Europe, though it is doubtful that this actually occurred.

Various online sources (ahem) mentioned a "cakewalk" craze in London and Paris around 1902-1903. The "cakewalk" is a both a syncopated style of music that predates classic ragtime and is also a dance. It's important not to get too hung up on the label as genre labels were pretty fluid--for instance, the "Swipesy Cake-Walk" above is not strictly a cake walk, even though it starts with a signature cake walk rhythm.

The cake walk really dates from the slavery era and it's reappearance around the 1890's is a revival of the earlier tradition. This page, while probably not up to /r/AskHistorians standards as a whole, is still fascinating due to the primary source materials it links to--postcards and films, particularly the demonstration of actual cakewalkers in the video contained therein.

The scholarly article it references describes the cake walk as being introduced in Paris by two American touring companies, "The Elks" and "Florida Creole Girls" Anyway, the cake walk was evidently known in Paris.

What brought me to attempt to answer this article originally was my knowledge of the popular 1903 musical "In Dahomey". Remember the World's Fair. In 1903, two vaudeville performers, Bert Williams and George Walker, in conjunction with famous black composer Will Marion Cook and writer Paul Laurence Dunbar, the latter two who attended the Chicago World's Fair, to write a musical featuring ragtime pieces [2]. You can hear ragtime strains in various themes of the overture.

Berlin [3] talks about "In Dahomey" as being a popular Broadway run as well as the first Broadway musical to feature an all-Black cast, but as I recalled from somewhere that it went on tour and premiered in London as well, to great success. I went hunting and tracked down this JSTOR article, of which I can only see the abstract but which confirms a similar success in London.

Returning to France and the article I mentioned before, the other piece of information that inspired me to respond was background knowledge that ragtime influenced the French composer Claude Debussy, who experimented with elements of it in his pieces "Le Petit Negre" and "Golliwog's Cake Walk". Furthermore, if you scrutinize the scholarly article I referred to, it provides numerous examples of French musical publications taking advantage of the cakewalk craze.

While I am sure that there are musically-focused historians here who can provide a broader context than I have been able to do here, I think it's clear that the answers to your questions are, respectively, "no" and "yes".

[1] Edward Berlin, "Ragtime: A Musical and Cultural History", p. 53
[2] Tertiary(?) source here--a Library of Congress summary of the Chicago World's Fair
[3] Edward Berlin, "King of Ragtime: Scott Joplin and His Era", p 165