Player List (your team's) - Minor League Players (subsection of player list).
is that under roster and transactions? should be enough to find it.
then, make some custom filters... by level, by position etc... whatever you want
then, make some custom views. make sure 'level' is included if you want to be able to sort by level and filter by position etc... if too much stuff, use 'short name' and maybe remove 'inf' column or other things not in use for you. e.g. whiel i do take a close look at splits, i do not list handedness, because i avoid platoons like the plague. if they can't play against both, i don't bother wit them... that means i can remove that column from view. i don't care which 'team' they are on, but i do keep short level name. i can get batters and pitching potential on one readable view for MiL players (the ratings i care about)
shortlists can help too. as far as minor league players i have 2 shortlists for players in my organization. Keepers and Trade Away (the trade away list can include mlb players too, some overlap there) i may only have a few keepers at certain points and more at others. players that are part of my future plans -- even if 'currently' that means 2 SS in minors developing... whichever makes it/scouted accurately etc... eventually one will fall off list to trade or whatever when a choice can* be made. *not necessarily when you promote to mlb, but can take that long.
don't trade for 'extra' RP. they are the worst trade assets of any position. you need rp depths, go ahead and accumulate it, of course, but only what you need. the elite guys and the right trade partner needs can make a few of them valueable. few and far between out of total pie
i also do the conveyor belt method
it's better they arrive early, because you can always trade the current player for more future assets. if you religiously trade your vets by 29-32 or so, you will have an endless cavalcade of high-quality prospects marching through minors. if they arrive late, you are in trouble or need to speend wastefully on a FA.
you can speed up the process and sign/use/trade FA before they get old, but that's a bit cheesy for some people, if this done in an abusive way to the spirit of the game. early on you augment a lot more with smart FA signings. later on it might be occasionally to fill a gap, but even that can be avoided.
trading any decent player is a better return than a compensation pick. only settle for a comp. pick for a player in severe decline or somehow not tradeable, like TCR.
trading for high-quality prospects is expensive. expect to trade multiple good players. shop helps, and improved this year, but just looking at a teams weaknesses on trade screen and matching up what you got will do wonders too. find a few equivalent targets... compare what it takes to get each and make the best decision.
a bunch of RP will never get you anythign in return, unfortunately... so, what you've accumulated so far has hurt you a bit as far as tradeable value.