Some not-so-common sentences baffling me

Eng.noob

1) New era in not only his academic life but also his social life. - a) Shouldn't it be "also IN his social life"?   b) Why not use "New era not only in..." instead of "New era in not only..."?

She was first in reading and (in) spelling. She was first not only in reading but also in spelling. She was first in not only reading but also spelling.  She was first both in reading and in spelling. She was first in both reading and spelling.  They're all okay, but if you want to skip the second "in" you need to place the first one before the modifiers (or conjunctions or whatever).

2) If ww do this, it should lead us to reflect on things much larger. - a) What is the meaning of the sentence?   b) Shouldn't it be "... much larger things" instead of "... things much larger" ?

Perhaps it means the larger things can't be identified (or reflected on) until we do this.   things (which are) much larger  places more emphasis on "much larger"  than does "much larger things."

3) I think its time we left this place. - whats the point to involve a past tense(left) when its easier to understand "I think its time to leave this place" ?  (that) we left   -   It has more of the sense of a done deal  -  of finality   -   than does proposing the act of leaving.  (I thought I had a good way to explain it but it petered out.)

4) It may be overlooked having regard to the fact that. - "... having regard to the fact that" ? I dont understand it at all.  You can usually replace the whole dang thing with "since."  (We usually say "In regard to the fact that"  OR  "Having regard for the fact that"    -    unless I'm mistaken.)

5) It is true of/for any social issue. - will it be OF or FOR ? If both are true, what is used when?

OF  -   Some statement would apply to any social issue.      FOR   -   If you did X, then Y would happen, in the case of any social issue.

6) The order came not a day too soon. - i dont understand it.  I couldn't have waited any longer.  Just in time.  If this were a day too soon, then it would be okay if it came tomorrow; but it's NOT.

7) This is right up there. -  what does it mean?  There used to be an old expression "right up there with the berries," but I can't find the origin. It means right up there at the top, or right up there with the big guys.  One of the best!