"I have been living here for the last 6 years and never felt so many tremors like in the past 6-8 months."
The tremors are there all the time but most of the time they are felt only locally, that is, you read on the news (or I do anyway, in La Nacion) that a tremor of
'x' was felt in 'y' but it was not felt in San Jose.
Also the theory that small tremors actually prevent the big ones from happening doesn't hold, the richter scale is a logarithmic one, that is, a 5 is 10 times as strong as a 4 and so on so it would take 100 tremors magnitude 4 to actually release the energy that a "big one" of magnitude 6 would release.
There is a major one that is expected on Nicoya because the fault line has not moved in a good while and according to records it moves every 60 years, buildings made in that area try to account for this in their design so that they don't collapse when it happens