@ the Original Poster
I am in no way more qualified to give advise more than USMCFLYER & RICKAIR7777, but I will try to add a few things, maybe they help. Pls don't mind if some words are too direct.
The more flying hours are good, but the effort must be focussed on your Destination & what you need to reach your destination. Don't go blanket flying with no aim, whether it is 135 or instructing...
Break your ULTIMATE BIG GOAL into small achievable targets & start putting an approximate Date on the things. Write your goals along with dates & post it on the FRIDGE or on your desk.....
If your AIM is airlines PART 121, then you need to prepare for that.
U already have 450 TT now, next you need to reach is 500 TT with 50 hrs MULTI, that will put you at the minimums reqd for Eagle & maybe Peidmont etc etc.
Next target, reach 700 TT & 100 Multi, which is minmums for ASA, next reach 800/100 which is Eagle 2nd level quals, next target 1000/100 for Skywest ....
Next target 1200/200 for the next level of airlines.
Somewhere along this time, you need the ATP 121 written knocked off with a decent score.
If U are still not hired, then U can continue with 135 VFR flights to reach 1200 TT for 135 operations & get picked up by a 135 gig. After 1200 TT, you should focus mainly on getting Multi time, not Giving joyrides in a single....
But U can give Joyrides in a Twin if U like... That will help.....
1500 TT is a threshold for a reason, you need to have X-C times, PIC requirements, IFR flying & Proficiency in flying in & out of Class B & C airspaces & shooting approaches like an PRO Airline PILOT, atleast 200 to 300 hrs on a twin, That is what having an ATP with 1500 TT means......
I am not putting this 135 VFR job down, get it NOW by all means, this will show you are employed in aviation full time. Infact, you will have something which even I don't have, a current flying job. But don't make it your HOME, always remember you are here only for a short time, KEEP MOVING to you next goal.
You can spend the next 18 months flying 135 giving joyrides & earning peanuts or prepare your self correctly & get hired in the next 6 months... If you do it right, it is possible that you will get hired before I do.....
Best of Luck.....