Covers are a lot about the overall feel and sometimes it's affected by the tiny details. Here are some little details that might help the impact of your cover.

1. Spiting a long word into two lines
It's rare to find a book cover in a store that does that. It mostly only happens in type centric graphics. Try either having smaller type, or just simply choose another title. 

2. Using a username instead of a pen name
Typography numbers, hyphens, and underscores feel different. and at times cause a distraction. Some people have extremely long usernames as well. Author names can be stacked, which might be the case for some usernames but not all.

3. Using an actor/celebrity as a face claim
I understand that some people write with actors in mind, but when everyone had celebrities as face claims everything starts to look the same, especially when there are fanfiction stories out there too. Not to mention that everyone likes to use the same actor. Try using models, open up the pool of people on book covers. 

This does not mean you can't cast your book. Go ahead and find actors for your characters but when you're using a familiar face like an actors, you're associating your character with the actors body of work as well. Where if you use someone who is not well known the reader can have more imagination over them. Remember, book characters do not always look like their movie versions so don't just limit yourself to just a "movie cast". 

4. Asking for a similar cover
Whether or not the designer made the cover that's being suggested, don't do it. Your book is not related to the original cover so why should they look like it's in a set (unless it's fan fiction I guess). Instead point out what you like about the cover that you wish could be incorporated into your own. There are a lot of tropes and trends but if they happen they should be done subconsciously.