It's when we get into objects such as clothing and votive candles when it starts to become cult-like.
I'm assuming when you say "clothing" you're talking about distinctive apparel like a Catholic clerical collar, Japanese robes for Zen practitioners, and the distinctive attire of Hare Krishna proselytizers or even Mormon (excuse me, LDS) missionaries. If that's the case, I agree. There's no need for Epicureans to adopt a distinctive style or piece of clothing.
That said, if a group of Epicureans wants to host a special event that encourages attendees to wear an ancient Greek or Roman costume, I see no harm in that as long as it's for the pleasure of attendees and seen as a fun part of the evening. It's a form of re-enactment. There are re-enactors of all stripes, from those recreating Roman soldiers to US Civil War and Revolutionary-era regiments to members of the Society for Creative Anachronism.
The issue appears to me to lie in the adoption of a distinctive piece of clothing that announces to the world that "Hey, I'm a member of X!! Look at me!! I am SO special!!" Epicureans, it seems to me, did live unobtrusively most of the time but were always available if someone was curious about the school. The wearing of a ring or a piece of jewelry is a way to remind **oneself** to "act as if Epicurus were watching." It's not meant to be an advertisement to the world that "I'm acting as if Epicurus were watching! Look at me!" Rings and jewelry and cups in one's own home are private reminders. Unless someone comes up and closely examines that ring or is invited to one's home, they're not going to know the items contain a portrait of Epicurus. That's where the wearing of a t-shirt with Epicurus on it might be questionable?
As for votive candles, if it's done in the spirit of honoring the person of Epicurus and/or the philosophy, I see no problem if it brings pleasure to the person setting out the portrait and candles. If it reminds someone to "do everything as if Epicurus were watching" Sic fac omnia tamquam spectet. Just like a ring or piece of jewelry, that seems fine. We have pictures in our homes of relatives and others that we hold dear. Having a picture with a candle of someone who provides a foundation for one's way of living doesn't seem so far out of bounds to me.
And to be clear: EPICURUS IS NOT WATCHING! He's dead. He's gone. His atoms have dispersed. It's his philosophy by which we've chosen to live our lives. It's the philosophy that he taught that provides guidance. A feeling of awe or respect for the founder should not be confused with blind adherence to some guru.
In thinking further along these lines, Epicurus and his philosophy are compared to light throughout Lucretius. For example:
O thou who first uplifted in such dark
So clear a torch aloft, who first shed light
Upon the profitable ends of man,
O thee I follow, glory of the Greeks,
And set my footsteps squarely planted now
Even in the impress and the marks of thine
...
For if must needs be named for him the name
Demanded by the now known majesty
Of these high matters, then a god was he,-
Hear me, illustrious Memmius- a god;
Who first and chief found out that plan of life
Which now is called philosophy, and who
By cunning craft, out of such mighty waves,
Out of such mighty darkness, moored life
In havens so serene, in light so clear.
...
Even Epicurus went, his light of life
Run out, the man in genius who o'er-topped
The human race, extinguishing all others,
As sun, in ether arisen, all the stars.
Wilt thou, then, dally, thou complain to go?
In light of that (pun intended), maybe a votive candle is not such a bad symbol to remind someone of Epicurus and the philosophy. Hmmm