Vertiente

Some options for translating vertiente (when it doesn't mean "slope"):

• field
  
• activity
  
• category
  
• aspect
  
• side
  
• consideration
  
• dimension
  

...and one context-specific one that worked well in a certain specific sentence:

• byway
  

Fortalecer, fortalecimiento

Here's how I've translated fortalecer [or resp. fortalecimiento] in past translations:

• strengthen
  
• support
  
• build up
  
• reinforce
  
• promote
  
• boost
  

and two context-specific solutions:

• enhance
  
• increase
  

Translation challenge: rezago

Note to self for future reference: solutions I have used for expressions involving rezago:

- set-back
- lag
- backward
- underdeveloped
- deficit
- gap

Diagnosticar

Ideas for translating "diagnosticar" when used in a non-medical (semi-metaphorical?) sense:
review, research, assess, investigate, explore, examine, question, look into, inquire, dissect.