lesser records in loops and more records in Traps

HI Experts,

I Have Studied Each and very forum regarding Loops and  Traps and Alias and contexts . . I got some Idea But still Confused. I Have went through Below Blog dave.

Dave’s Adventures in Business Intelligence » Context Versus Alias Overview

i got conclusion But still I am Confused and have some questions so that its time to shoot out Questions .hope some one will answer my questions and make me out from this confusion

Here are the Questions that i Have from so many days

1. Why Loop Will get less Records whats Logic is there in Backend? can any one explain with example

2. Why Trap will get more records? can any one explain with example

3. IN earlier while doing POC  i face situation Many to Many Joins between tables as dave mention you should correct your data model?

What does it mean? When we get wrong results with Many to many joins which approach I need to follow?

4. What will happen  if  Fact table--> Fact table--> Lookup table with 1,n,1 will it be a Trap?

and Fact table--> Lookup Table--> Fact table with 1,n,1 will it be  Trap ?

I Am Confused a lot in all these things .

Any One could explain clearly Really  Highly Appreciated

Thanks,

Varun