The coolest sounding language has to be the French. It is considered a universally attractive language because of the way its words are pronounced.
The smallest language in the world (which inherently has the smallest vocabulary) is the "Toki Pona". Its vocabulary is a mere 123 words, which is miniscule especially when compared to the vocabulary of Koko the gorilla (an infamous domesticated ape), with over 1,000 words and gestures.
It is impractical (and unrecommendable) to learn five languages simultaneously because the learner needs to understand multiple language concepts and converse using the target languages at roughly the same time in order to develop a strong foundation for each language. It is theoretically possible, but highly improbable.
The two feminine versions of the name Richard are "Ricarda" and "Richenda".
There is no current female version of the name Arthur. However, one can place suffixes to the name such as '-ette, -ina, or -ia'.