This is a personal opinion:
1. Why hold back on photos? Free to host, free to upload. If I was looking for that lens with £120 burning in my pocket, and the choice was between an item with no photos or an eBay example with good photos, it's an obvious decision. Absolutely no excuse for this with smartphones in abundance.
2. As previously mentioned - shouting NO OFFERS is your prerogative, but when your item is priced similarly to eBay examples, reduces your potential buyers further
3. Small market - niche use lens, compatible with only select Nikon (DX)
4. I've always had no issues trading on this site, but there is always a risk of sending money to strangers, especially for larger transactions