How to 'build' my moderation variable

#1
Hello guys,

I'm currently busy with thesis, but I have a question about my moderation variable.

In my research I'm exploring the relationship between political orientation (independent variable) and vaccine readiness (dependent variable). I'm hypothesize that the effect of political orientation increases if a person experiences less barriers in the process of getting a vaccination. I have no 'ready to go' variable, so I have to make one. And I have all the ingredients for that variable, but no clue how I can make the moderation variable. What do I have?

1. A variable about language skills (oral) - How good does the Respondent understand the [Dutch] language when it is spoken? Answer possibilities: (1) I don't understand Dutch, (2) sometimes trouble with understanding, (3) no trouble with understanding
2. A variable about language skills (writing) - How good is the Respondent in understanding written Dutch? Answer possibilities: (1) I don't understand Dutch, (2) sometimes trouble with understanding, (3) no trouble with understanding
3. A variable about ethnicity; respondents had to answer if they are (1) 1st generation migrant, (2) 2nd generation migrant or (3) non-migrant Dutch
4. A variable about ethnicity; Respondents had to answer if they are (1) non-western migrant, (2) western migrant or (3) non-migrant Dutch
5. A variable about education; Respondents had to answer which type of education they did (1) primary school, (2) [lowest level] of secondary education, (3) [highest level] of secondary education, (4) vocational education, (5) university of applied science or (6) university
6. A variable about income. This is a variable where respondents had to give up their gross monthly income.

All the highest scores of the six variables indicate less barriers according to the literature. So have can I make this all in one variable?

I already tried the following: I did not changed variables 1-4. I made a ternary distribution of variable 5; categories 1&2, 3&4 en 5&6. I did the same thing for the sixth one. category (1) 0 - to the social minimum, category (2) social minimum - modal income and (3) modal income - all other highest values. Then I made a scale of it (so added all scores up and averaged it). The crombach alpha is 0.524. The result is a continuous variable from 0 to 12 where high scores indicate no barriers en 0 lots of them. But how good/wrong was my method? Is there an better way to do it?