linkages among variables - aggregated data

[ninaseptina]

Dear All,
I prepare a study on 5 variables as follow that A and B are employee (N=141) variables, C and D are customer (N=987) variables, while E is company (N=47) variable. A has two reflective indicators. C has 3 reflective indicators. B has 4 formative indicators. D has 3 formative indicators. E has 2 formative indicators. A has linkages to B and C, while C has linkage to D. Each of A, B, C, D have linkage to E.
To find the linkages among these variables, individual data (employee and customer) will be aggregated to company level which they connected each others. This procedure leads me to some questions.

1. Is it statistically allowed, for transform the data like this? Where I can find literature to support this procedure?
2. Should aggregated data be in the form of summated score or average score? (The questionnaire responded by 5-point Likert scale)
3. How to put this model into the mathematical equation?
4. How to run the model with smartpls?
5. What I can expect from smartpls for this model?
6. How to interpret the result?

Thank you very much in advance. Have a nice day.
Best regards,
Nina