I only have info about the RE path there.
Some hidden issues were outlined in earlier posts of this thread.
I’d say the main ‘issue’ is finding an eligible RE asset to buy, as only a subset of properties on the market would be eligible for various reasons, such as to name a few:
- the seller must be a Turkish citizen
- the full purchase price must be shown on the title deed, which is NOT a normal practice, hence this further narrows the scope to:
- older than 5-year old properties
- only those sellers who are happy to show the full price
- then also the official evaluation report price is another limiter, as the investment excess above the official evaluation does not count
Once the property is chosen the buyer should be careful in ensuring it has the habitation licence as it cannot be assumed (that is similar to PT in fact). There are in fact two habitation licences - one for the building, and another one for the apartment unit in that building (obviously a standalone house/villa would only have one).
If one reads TR English-speaking forums, people advise there that one must ensure both licences are in place.
But I found this advice a bit over-the-top ‘Western’-type view. In practice it is common practice NOT to have an individual licence, but only rely on the building licence.
Lawyers would check that but always best to know what they are checking and challenge them to show evidence of that. Lawyers obviously would want to cut corners if the buyer does not watch over them like a hawk 
‘Family reunion’ is more stringent than PT, in that only the partner and minor children are eligible to join the main applicant. There are some technicalities further on the documentation requirements but I’d say nothing too scary for anyone familiar with PT GV.
I’d say these are the main points to be aware of.