Fixed and Randomized dungeons? speech dialogue, RPG progression, battle and item System? i can't think of a single mechanic Skyrim has that you couldn't recreate in Construct 2 in some form, however, if you want to get Skyrim level of details, you will probably stretch Construct 2 before you even get half finished.
This guy made good progress with an RPG but was forced to switch to Unity because of Construct's limitations.
https :// scirra. com / forum/my-isometric-rpg_t151431
Also, i am not sure 3 years is nearly enough for a solo developer to create a 2d open world side scroller in the level of details Skyrim has.
Thank you for the suggestion! I see he mentioned some limitations like 10.000 image limit.
Most probably I would not make such a powerful game, but I would just finish the game if I was about to hit the limit.
I will split the project on several games and then combine them together into one on Construct 2.