You're totally correct. In fact this suffix shows up in the famous name "Dracula". This was originally 'Drac-ul', "the dragon", the title of Vlad II of Wallachia. His son, Vlad III - the ruler associated with the Dracula legend - was then called "Dracula", a Slavicized form meaning "(son) of the dragon".
Hi, Eric_Allen. If the noun ends in "e", "ă" or "a" you know it is feminine. For the one ending in "i" it is not that simple: zi - day (feminin), ardei - pepper (masculin). The rest are masculin or neuter which behave similar (have the same article "ul").
In my head, I cannot find exceptions to this rule right now.
Once thee can hear it on the slow speed, always go back to the regular speed until thee can hear it (but don't despair if thee can't; sometimes it's actually not there!). This will help immensely when thee finally gets to chat with native speakers. Thee won't need to interrupt them every 2 seconds to ask them to speak slower :)