in answer to first question, what you said not only isn't the problem but the only reason for our survival to this very day.
so who wants to control Persian gulf? our navy and their classic methods?
with exactly how many ships and budget you plan to counter the U.S navy?!
being lazy and stagnant is the main aspect of our army. go read how Tehrani moghaddam created our missile forces, were was that lion's share when he was working in a tent beside the streets?!
If it was army, after wasting a good share of budget, begging this and that country, their today's achievement would be copying and chanting about upgrades on scud missiles, just like their current state, each year talking about upgrading the Zelzal missiles! like what they are doing in the airforce, celebrating the upgrade of an F5 simulator in 2016.
IRGC develops it's toys and gives them to defense ministry for mass production, while army prefers to wait for defense ministry. and if it wasn't supreme leader's order, they wouldn't have started the moj projects too.
You see, It's a kind of thought in which you can suspend a fighter project with the excuse of lack of budget while talking about heavy contracts to import an (already out of date) fighter without anybody mentioning about budget.
regarding economic activities, IRGC just wanted to use it's free capacities to fill the gaps not to impose itself. if it wasn't IRGC then it had to be foreigners which is equal to more imports and dependence. is it what you want?! do you prefer korean workers to build your refineries and shut down the project whenever they want? do you prefer to Chinese work on a decades old highway and then leave the project in the end?
though there are people inside and outside who want that!