How many actions per turn OK?

First, if people are forgetting phases, print up a reference card with the different phases on it. No one will actually use the thing, but it's nice to be able to say, on the 20th time someone asks what they do on their turn, "well, as it says on your reference card..."

There's probably no right or wrong answer to your question, but the biggest consideration is probably down time between turns. In a 5 player game, if each player's turn takes X minutes, then a player must wait 4X minutes between his turns. If X is too big, and he's not involved in the other players' turns, this could get boring.

I note that in your game, there's trading (between players, I assume), so downtime may not be as much of a problem. If you find that it is, you could consider doing things differently while preserving your overall structure:

Instead of players doing all actions during their turn, have each action be a "phase", in which all players will act prior to proceeding to the next phase. So, first, all players would take points, then all players would buy tiles, and so on.

In one of my games, I had a turn sequence like this, but having everyone take every action every turn was making the game too long, so I instead went to a model where each game turn, you could only take a limited number of the available actions. So, in your game, for example, maybe I only get 2 actions per turn, and if I choose to buy tiles and trade, I wouldn't be able to take points or move, for example. These kinds of restrictions can lead to a feeling of "wanting to do more in your turn than you're allowed to do", which leads to a very satisfying source of tension. The games of Wolfgang Kramer (e.g., Tikal, El Grande, Maharajah) typically have this kind of tension.

Good luck with your game!

-Jeff

The idea that people can store anywhere between 5 and 9 units of whatever in their short-term memory is sometimes called "the rule of seven plus or minus two".

However, the reality of the situation is a little more complex. We are really only capable of reliably storing and operating on 3 units at a time if the units are not related to each other in some way. We end up storing and operating more than this, typically, because we group the items to be remembered in our minds in groups or structures of categorization. Imagine that human memory is like a tree of directories on your computer, and it's easiest to store any given structure of directories in memory if any given directory contains 3 or fewer directories or files. Psychologists call the mental equivalent of placing the files into the same directory "chunking", and the directory itself is called a "chunk".

The more distinctive and logical the grouping is, the more easily it is remembered. For most people, practice that shows us a consistent ordering (like any other consistency or association between units to be remembered) will automatically group units in our minds after some time of play.

So if you have a large number of phases (or anything else, for that matter) for your players to remember, you'll want these phases to be "groupable" in the players' minds. People are pretty good at doing the grouping thing automatically, especially after practice, but your game will just be easier to understand and pick up quickly if you work with the ability of memory to work better with categorizable or "chunkable" data.