Asgard

1. I keep shrimp in small tanks, started with a:

6L, RCS, no heater, no filtration, in the windowsill, no (well, almost none) direct sunlight, no cycle start, weekly water change of 1L-2L. much like some people keep their betta or goldfish. Javamoss, Anubias nana, Eleodensa sp. No major problems.

17L, RCS, no heater, filtration AquaFlow 100, no cycling, no problems, weekly water change 2L-4L

54L Bee shrimp with D. margaritatus (galaxies), Applesnails, Atyopsis Moluccensis, Standard Juwel Rekord 60, no heater, no problems

60L RCS cement tank, outside, no filtration, no heater, plants: mainly Eleodensa an Javamoss, RCS population survived the winter, even frost.

In the 6L, 17L I have had planaria, Flubenol was the solution, great stuff!

2.
Cherry shrimp, they were the cheapest.

3.
Waterchanges, shrimp can't handle NO2. if you start with a new (un-cycled) tank, change 10% water daily for about a month, then weekly 10%-25%, do that and you don't even need a filter.
If you keep Cherry, Bee, Amano shrimp, don't use a heater, they are sub-tropical species from S.E. China, Taiwan, Japan, N. Korea, they can handle low temps and prefer day-night temp. changes.
Flubenol 5%, sooner or later you'll have planaria or other invertebrate pest. Save for shrimp.