Difficult to know what you want as your post is full of contradictions but Weak Auras 2 can give you a text message on screen based on certain events (like cool downs becoming available) and an addon like CoolLine shows a permenant bar on your screen showing upcoming and multiple cooldowns etc.
If you use any Bossmods like DBM/VEM/BW you can just setup a simple macro and start it at the start of combat.
Example of said macro:
/dbm timer 100 Use HEROISM
/dbm timer 120 Use TRINKET 1
/dbm timer 360 Use TRINKET 2
It's not entirely convenient but uou can setup your entire combat time like that and be notified with both a progress bar aswell as text messages about stuff to do .