Q's from a new player

Hey there, just started recently (Steam Sale and now PS4 beta) and have a couple of questions I hope people can help with:

1. When I see items in my inventory, they often have a coloured dot in the top right of the items icon - what do those dots mean?
2. When I hit level 10 in my first class, it tells me that I have points to spend on my abilities - do I spend/save these?
3. Do I only get these points in my main class when it levels or every time I level with a class?
4. Do I have to think about spreading the points out to cover the bases for all the different classes I level or can I spend Conjurer points on the relevant abilities and then (if) I get points when levelling Gladiator I can spend those points on those skills?

Thanks in advance!

1. The current dye color. The dot only shows up for gear that can be dyed.
2-4. Spend them. Each class gets its own pool of points to spend. So when you put everything into STR on PGL/MNK, then switch to CNJ/WHM, you'll get a fresh pool of points to put everything into MND. Each class you level is basically a blank slate. The only way they effect each other is the selection of cross-class skills you unlock by leveling other classes. A level 10 GLA is a level 10 GLA, whether it's a brand new character or the last class that isn't 50 on that character.

The only class (for now) where the bonus points are something of an issue is ACN, because it's the base class for both SMN and SCH, which favor INT and MND respectively. Most players either split the points evenly (if they want to play both and don't mind being less effective on both), choose one over the other (if they mostly play one job and only do the other now and then), or respec when they switch (there are items you can get from your GC for 10,000 seals to redo the points on any given class).

1) I'm not sure about what you're talking about ><.

2-4) Spend them! Usually people add those points to their job's main attribute. They do not unlock skills - just add some basic stats. As a conjurer - you're gonna unlock the White Mage job. So I'd suggest you add those points to Mind, the attribute that improves your healing rating. :) Do not worry too much about it though -you will be able to purchase an item that lets you reset them if you feel the urge.

3-4) Every time you level any class - and they're class specific. Right now, you only really need to worry about it if you plan to level an Arcanist - since it's the only class that unlocks two jobs - a dps and a healer. Some arcanists put all of their points in one attribute - some split them. At the end of the day it doesn't really make that much of a difference though- unless you really care about min-maxing.