Don't do akaadians build against that team comp man ._."...
Seriously make 2 rune pages keep one for that akaadian stuff and do the other one where you desperately need early game presence and can't afford to be losing your health to jungle camps and being overly greedy.
Look at your last game. No one does damage early game on your team. Vayne has to depend completely on maokai to engage because everyone else is an easy kill. Full AD One-Shot Rengar is going to be useless when they group up because you have the potential only to take out annie and graves. A good thresh will just ult flay and block your leap. Also when you engage using empowered Q graves has mobility and a thresh to follow up, annie has a 1000 AP nuke. graves has it ultra easy because he has 4 initiators for him. Heca ult, malphite ult, annie tibbers, thresh Q Q R E Maokai engages and then what ? who is vayne going to attack? hecarim realised that your team comp has no damage so with the thornmail + warmor combo along with exhaust, he could probably aa your damage line to death.
This is a game where you either end it in 25 -35 mins or everyone dies man ;_;"... Complete the trail blazer. or just run a Tiamat first item directly after machete and start nuking everyone. As soon as you nuke, translate that into a tower. Just agressively push. Once outer turrets are gone, start deep warding all their jungle exits and make picks. You need to tell your support exactly where you want the wards and you need to know exactly what they are going to counter.
In simplicty You need alternate build paths and alternate rune pages. High damage rune pages are fun but not when your entire team is compromised.
Even in the previous game, they have hecarim and malphite and you build a trinity force... What is graves supposed to do ? he has no front line. What is morgana supposed to do ? do you expect her to initiate and get a 5 man ult done with her zhonyas ?
Game before that, Jinx is doing massive damage, Zed is doing massive damage, you are doing massive damage. Who initiates ? Lulu will ult anyone you try to 1 shot, and then you get nuked in turn. Check out the statistics. You took the maximum amount of damage in it. Please just consider other builds and play styles with rengo :c, He is really really fun as a one shot rengar, but that just doesn't work in certain comps and situations.
A rengar main @DrJakey on this forum linked me to his guide
http://www.lolking.net/guides/292980
and it by far the most in depth guide I have seen and it has sooo many situational choices. Have a go through it, try some new things. Make rengar play in other ways :)
I hope I helped in a little way. I am below your elo, but I am a nerd when it comes to theory crafting, maths and analysis >_<"....