Migrated old forum, need some advice please

[Outlaw Mantis]

So my old forum was on MyBB. Migration has gone fairly well so far, but there are some things I need to fix and plugins that I'll need to find the best solutions for. Yes, I have searched for some of these plugins, but for some there are a few. I'd like to hear what you think would be the best option.

Problems

• My UID is 1, of course, with my user name called Mantis. Unfortunately, a few of posts for some reason are by "imported_Mantis", as shown below. I don't know how to fix this. This imported_Mantis user name is a couple above the current members, 189, whereas the number of members is 187.
  
  
• In the navigation bar I want to have an "Egosearch". This allows members to search their own posts if they wish. Any way to do this and have their UIDs' in the URL? I know they can just go to their profiles and search that way. I just find it more convenient to click at the top of any page.

Plugins

• Money System
  This was a key feature on the old forum, and it is virtual money, not real. It also had a shop where I had items that people could buy with the money gained from posting, time spent on the forum, creating threads, amongst other things (explained later). In addition, it had a bank system which supported interest when money is deposited, and also a lottery.
• Achievements System
  On my old forum, this allowed achievements for various things similar to what gets you money about, and you could also create "custom achievements" which you award manually. It also supports ranks/levels based on which achievements you've gained, like levelling up.
• Arcade
  I already know ibProArcade and I used a port of it on my MyBB forum. I'm going to add all the money information for the money system and a lot of other things manually by editing the SQL. However, the arcade must be compatible with the money system.
• Image Gallery
  As it says, an image gallery that has categories and is quite advanced, perhaps also allowing other members to comment on images. (Not required.) I also don't want other members to post images, but I guess I'd be able to disable that.
• Download Centre
  Members will be able to pay with the money (virtual money, like above) to download files on the centre. Also advanced options perhaps to allow "locked" parts of the centre to certain member groups would be nice.
• Wiki
  I've come across VaultWiki, and I think it looks terrible, sorry to say! I had a simple wiki on my MyBB forum. You can see a screenshot of it here. Any ideas?
• Avatars in Forum Listings
  I hope I worded that right. As you've probably guessed, small versions of avatars will be shown to the left of thread titles for an easier way to see who posted the thread.

I don't want to be spoon fed here. I just don't know the best options, such as the wiki for one big example. So if you could help me out I'd be massively grateful. Thank you!

Edit: Okay, I fixed a lot of these, but not all. I'll make new threads. I think it's more likely I'll get responses if I post the issues in separate threads.