Desired future direction: Dynamical System(Chaos), PDE
More beneficial to read theoretically deep, modern and masterpiece texts earlier, (e.g. levels like UTX/GTM/GSM/LNM/CSAM) ? Especially in core areas (e.g. Analysis, Algebra, Topology etc.)
i.e. Read briefly less for intro-level, then quickly drop to the deeper/modern texts, although basic skill's not trained enough, but to be trained again/better in 'deeper-stage'. (Sometimes it seems learning new material in deeper/complex 'environment/context' gives better/faster maturity.)
e.g: Calculus/Analysis: Apostol -> Hardy, Courant, Stein, Rudin, Amann
Linear Algebra: Axler -> Dym, Grueb, Lax, Halmos
Algebra: van der Waerden -> Lang, Hungerford, Jacobson, Bourbaki
Topology: Kelley -> Milnor
"for topic of calculus, I spent long time on many books of intro level" definitely sounds like a mistake. I would not advise anyone to read many introductory calculus textbooks. (Unless you serve on an undergraduate committee or plan to write a textbook of your own.)
It's hard to find anything wrong with reading deep and modern masterpieces early. Some amount of struggle and confusion is healthy. There is a simple way to find whether such advanced reading is beneficial: try to explain what you read to someone else (e.g., to an imaginary blog reader :).