Online task planner + note storage?

Question

Task Management

Brothers, by the will of fate, I’m currently working in two different redmine plus I’m trying to plan something in the Google calendar - and it’s all somehow hard. There are a lot of my own small tasks with low priority and no due date, it is impossible to cover everything with one glance, it is difficult to control, etc. Decided on the opportunities I personally need, can you tell me if there is such a thing in nature.
So.
Task scheduling

1. Presentation of tasks in the form of a flat list
   
2. Ability to assign tasks both with a fixed date and without (make it possible)
   
3. If the task is scheduled for a date and not done, it does not go into the past, but somehow ... hangs in the future additionally selected
   
4. To have some kind of notification logic when accumulating such “transferred” tasks, and tasks “without a date”.
   

Storing notes
Historically, I have one text file in which some key pieces are stored. There… logins and passwords, some with addresses, electricity meter readings, pieces of instructions for signing APK files, etc. This information does not require special structuring - just blocks and that's it. But periodically, individual pieces change - passwords, instructions, etc. I would like to keep these notes in the same place where the tasks are. But by analogy with git - so that you can have a list of changes for each note with dates, and get the state of the note for the desired date.
General requirements

1. Be sure to need client-side encryption-decryption. Those. so that information is stored in encrypted form on the server, and encrypted-decrypted on the client.
   
2. Availability of a mobile client for Android
   

Answer 1

Evernote + plugins

Answer 2

Doot.im try it.

Answer 3

an interesting thing Sap StreamWork
is not really, of course, sharpened for notes, but a good functionality for lists, priorities, decisions, etc.

Answer 4

teamer.com

Answer 5

myagenda.ru/

Answer 6

Try www.timeact.ru

Answer 7

I use mynotes.su to store notes .