Ask three meadmakers how to make mead, you're going to get at least a handful different suggestions.
Your mead very well might taste pretty good right now. Give it another month, it'll taste better. Six months, even better. Better than many commercials, even. A full year, it might be downright delicious.
It's probably fully fermented, but it's very unlikely it's dropped perfectly crystal clear. Those microscopic bits of yeast, pollen, wax, bees' knees, etc, will settle out over time. They muddle the flavor. Even perfectly clear, time will continue to improve the mead. Alcohol warmth will subside, honey flavor and aroma will come to the fore. Time is mead's most precious ingredient.
I'll typically do 2-4 weeks in primary, then rack to a fresh vessel with oak cubes for three months. When that's done, bottle. That's just me and my process. There would be no harm in leaving the mead in primary for 2-4 months, if it was appropriately sized and able to be closed from the atmosphere.
Time will improve any young mead. The longer it's in any particular vessel, the less particulate will make it to the next. Perfectly clear mead in the bottle with nearly zero sediment is possible.
As far as adding anything, sure. Sky's the limit. I have started using oak in all my traditionals to add a bit of tannin for interest. The previous batches were fine, but a bit flabby.
