Alan I-Fang Liu, MD

I would suggest schedule an appointment with a hair transplant surgeon for a more accurate number.  2500-3000 graft is a rough estimate.

Every steps of the procedure is important, but extraction might be more important.
Using implanter pen minimize the possible minor trauma induced with the slit method.  However, skilled physician is more important then the method that they choose.

The hair coming out when you shower is normal.  But the hard nodules might be possible inflammation and might require medication.  I would suggest you book an appointment with your doctor to take a look.

It's really hard to answer this.  Severe sunburns with blisters do have the possibility of injuring both the transplanted and original hair follicles.  Transplanted hair is not more vulnerable after 8 months post-OP.  However, most of the time it will grow back.  Good care to avoid scalp infection will be the most important thing now.  Wash your hair everyday gently.

Sorry your picture is not very clear but don't worry you will see more hair growing out in the future months.  Also the density looks quite okay for a 5 months post-OP.
But end result regarding the density of the hair really depends on your demand.  Sometimes female hairline do need second surgery for thicker density.