Can negative feedback in OPAMP be applied at not inverting terminal?
Yes the logic of feedback polarity in the loop must be negative applies to linear feedback.  The same rule is used in analyzing stages of inversion for transistors inside the Op Amp.


  i.e. yes in your case,  you swap the inputs 


But as frequency increases and bandwidth limits there exists a phase lag which accumulates to 90 deg per 1st order effect and must be compensated internally to prevent positive feedback oscillations at the unity gain max frequency. Since OA's typically are compensated to only 60 deg margin, unity gain stability is not possible without filter 1/s compensation.

For stability criteria, you should not expect unity gain stability in other words unless compensation is understood. (Barkhausen criteria)  But you will learn this later.

Also understand that OA's have current limits so observe minimum  R feedback .. > 300 or > 10k for CMOS types.  



Swapping inputs with inverted feedback to Vin+ makes this a negative feedback circuit again.