How to hide map icons?

[Planetdune]

Screenshot:
https://all-outdigital.com/temp/hidewow.jpg

1. How do I hide/remove that diagonal arrow (top right of map)? I keep misclicking it when trying to close the map and it screws over my map layout.

2. How do I hide/remove Fiona's Caravan from the Eastern Pleaguelands map ? It obscures custom handynotes icons I created.

3. Is it possible to hide the "info" button (the circular i button) from all UI panels?

4. Is there an addon that allows you to enter a quest ID on a box and it tells you if you completed it? (I know this can be done with a script command but it is cumbersome to keep having to look up the script and copy paste it in wow/change the id).

[Axaion]

Youre not misclicking it, the "hitbox" of it actually overlaps the X icon

Blizzard at its finest.

[Deleted]

2. How do I hide/remove Fiona's Caravan from the Eastern Pleaguelands map ?

you can not do that.

[Kanegasi]

The following will fix the map button issue:

Go to http://addon.bool.no and paste the following in the lua file box:

local f = CreateFrame("frame")
f:SetScript("OnEvent",function()
    WorldMapFrame.BorderFrame.MaximizeMinimizeFrame.MaximizeButton:SetHitRectInsets(6,9,8,8)
    WorldMapFrame.BorderFrame.MaximizeMinimizeFrame.MinimizeButton:SetHitRectInsets(6,9,8,8)
    WorldMapFrameCloseButton:SetHitRectInsets(6,9,8,8)
end)
f:RegisterEvent("PLAYER_LOGIN")

Name this whatever you want in the AddOn folder name box.
Click Show advanced (TOC) options. and change 70200 to 70300.
Then click Create my AddOn and give me my files! and unzip it into your Interface/AddOns folder.

For the quest completed lookup, you can sign up for API access here: https://dev.battle.net/member/register

Then use this link:
https://us.api.battle.net/wow/character/SERVERNAME/CHARACTERNAME?fields=quests&apikey=THEAPIKEYYOUGETFROMTHESIGNUP

Make sure to replace the all-caps parts accordingly, as well as using your region at the beginning, such as us.api.battle.net or eu.api.battle.net.
You will get a page full of text that looks like the screenshot below, just ctrl+f the quest ID: