lol Its quite alright. This is the best place for questions! 
Honestly Im not sure about the loan relationship, mine arent through Sallie. If your TU score gets up to around 680 or higher in the next six months and you dont accumulate a lot of inqs in the meantime Id say you'll be fine. Dont think Barclay is as conservative as some claim but it varies. My score at the time was 696 but Ive seen lower get approved. For a 3rd card I think a straight 2% cash back on everything would work for your spending so recommend Citi Double Cash. Before you apply for anything Id wait until Discover reports for at least 3 months and then see where your scores are, btw your TU FICO you get monthly with Discover for free. I got a significant score boost when my first revolving account started reporting. Ideally you want at least three cards reporting but you dont absolutely need three nor do you need to rush and get them all at once! Would stay away from store cards...but thats a personal preference thing.
Honestly Im not sure about the loan relationship, mine arent through Sallie. If your TU score gets up to around 680 or higher in the next six months and you dont accumulate a lot of inqs in the meantime Id say you'll be fine. Dont think Barclay is as conservative as some claim but it varies. My score at the time was 696 but Ive seen lower get approved. For a 3rd card I think a straight 2% cash back on everything would work for your spending so recommend Citi Double Cash. Before you apply for anything Id wait until Discover reports for at least 3 months and then see where your scores are, btw your TU FICO you get monthly with Discover for free. I got a significant score boost when my first revolving account started reporting. Ideally you want at least three cards reporting but you dont absolutely need three nor do you need to rush and get them all at once! Would stay away from store cards...but thats a personal preference thing.
Do you think all my scores will be similar to my TU fico? - It varies. All three of my reports have exactly the same information yet EQ is consistently lower than the others. They may all be in the same range but dont count on them being identical.
So how long do you think it should take to collect three cards? - It depends on how quickly your scores rise, profile improves and when you feel comfortable applying for more. Like I said give it at least three months before the second.
Also, how long should I garden after that? - As long as you wish. Six months is usually a decent time but you may want to try for your 2nd and 3rd cards simultaneously, hard to tell at this point.
Do you think it would be fine to apply for more after gardening for a year? - A year should be perfectly fine, just make sure you actually have a need for the cards you choose.
What card would you recommend after that? - Lets get the first three going and then revisit this later.
I just really want to develop a couple year plan so I know what I'm doing. - Its hard to develop a plan years into the future. Your needs could change as well as your profile, life happens. 3 - 6 month plan is reasonable. Pay your bill on time and only let 1-9% util report whenever you need to maximize your scores. Give it some time and you'll be in a good place for the next cards soon.
So how long do you think it should take to collect three cards? - It depends on how quickly your scores rise, profile improves and when you feel comfortable applying for more. Like I said give it at least three months before the second.
Also, how long should I garden after that? - As long as you wish. Six months is usually a decent time but you may want to try for your 2nd and 3rd cards simultaneously, hard to tell at this point.
Do you think it would be fine to apply for more after gardening for a year? - A year should be perfectly fine, just make sure you actually have a need for the cards you choose.
What card would you recommend after that? - Lets get the first three going and then revisit this later.
I just really want to develop a couple year plan so I know what I'm doing. - Its hard to develop a plan years into the future. Your needs could change as well as your profile, life happens. 3 - 6 month plan is reasonable. Pay your bill on time and only let 1-9% util report whenever you need to maximize your scores. Give it some time and you'll be in a good place for the next cards soon.