Hi Phio,
linéaire.com : correct, but adjective, and an adjective does not stand alone although there are exceptions (gratuit.com, belle.com, ...).
ampère.com : correct, can stand alone
arrosée.com : correct, adjective in the feminine form, does not stand alone well. Has different meanings : a flower or a plant can be arrosée (watered) but a party can be "arrosée" or even "bien arrosée" (watered but with alcohol
)
accentués.com : correct, adjective in the masculine plural form, does not stand alone but with a subdomain would be OK : domaines.accentués.com
récents.com : correct, adjective in the masculine plural form, does not stand alone very well
tâche.net : noun, correct, stands alone
latâche.com : correct but in the general opinion articles + nouns domains have no or little value