Your question needs more clarity, mate. But at face value, 'that name was very interesting to them' simply means that the said/given name was peculiar or unique (draws curiosity).

Your question needs more clarity, mate.

Objectively speaking and by nature of each word's natural potency, 'extremely' is much more stronger. However, based on what you are saying (context included), 'very' might roll of the tongue easier and be the better option.

Simplemente, a mi juicio claro que sí, —un resumen: dice algo en tus proprias palabras manteniendo los puntos esenciales. (una versión corta de un discurso o un texto) Por cierto, un resumen puede ser escrito u oral. —Discurso : una elaboración de un tema. — Recorrido: no tiene nada que ver con un discurso, un resumen ni una redacción . ¿Pero quién sabe ? Tal vez me equivoco

Where I am from, they mean two different things. 'To be rooted' as we use it is a sense of 'to be based'. For example, the practice is rooted in Christianity. That is to say that the specifc practice is based on Christianity. Similary, we are deeply rooted in... whatever. However, it is not an expression to just throw around. Usually, these expressions have 'set' (acceptable) instances. On the other hand, it is possible to give the phrase a metaphorical/literary meaning. He is rooted in crime, so he cannot be saved. Here I could assume that he is stuck or just deeply affiliated with crime. But I suppose if you so, I am rooted in traffic.... you would be understood. Our minds are not that basic to not comprehend a coined expression. However, you won't hear your typical guy shoutig it. P.S. The next time you ask a question, give a context. That helps.

Really and truly, I cannot think of a context in which anyone would say 'he has told me'. It just sounds unnatural. This isn't about rules of grammar now, just what sounds natural and what is actually used. However, note, I am not saying that 'has' cannot be used with it the participle, because it can. For example, has he already eaten? Anyway, to fully determine which is correct, you must give us a context or flesh out the sentence.