Guild Wars 2

So I just changed my build to Inventions and alchemy and I wanted if anybody could give me a few pointers. Like what should my skillbar look like, what weapon should I use (rifle I’m thinking?).

I think your approach is a bit back to front:

In what context (PvE/WvW/PvP) do you want to play?
What do you want to achieve with your build? Bunkering of some kind i suppose.
What Weapons and Utilities do you LIKE to use?

After that decisions you should start looking for the fitting traits, not the other way round imo.

As your choice doesnt define a preference for any damage type you can use either Pistol MH + X or Rifle equaly… mediocre (with Inv. Alch. youll never be doing impressive damage)

The Inventions traits support using Turrets or Bombs , the Alchemy traits are almost totaly focussed on Elixiers.

If choosing turrets to be supported by your traits id say go for conditiondamage and therefore Pistol(s) as weapon, since turrets are taking into account your condidamage stat.
If prefering bombs you could go either way, as bombs profit from power as well as condition damage.

In both cases elixiers will be your best bet as additional utilities.

Im currently using a 10/0/30/30/0 Setup for tPvP Bunkering, using Elixiers plus Bombs as Utilities.
Weapon choice (and amulet) change according to closepoint or mid positioning:

For CP duty:

http://www.intothemists.com/calc/?build=-W70;2Z;0i0c-FQFx0;9;49-TT-2;303A159;1U;5qNnCrBl34By

for mid/groupsupport:

http://www.intothemists.com/calc/?build=-WRw;2Z;0i0c-FQFx0;9;49-TT-2;306A159;1UN1;3qNnCrJG49cW
or
http://www.intothemists.com/calc/?build=-WRw;2cP-i0c-NQFx0;9;49-TT-2;306A15B;1UN1;3qNnCrJG49ce (for extremely condition intensive opposing groups)

Note:
in all builds im still experimenting with Runes… for the pistol-setups i like Monk/water/Lyssa best
full forgerunes could play out well too, probably better in conjunction with Elixier C, Alch. XII, Healingturret as the boons provided by H and B are missing.

I do a build with Inventions and Alchemy as well, with 10 in Tools. It’s a healing power/condition damage focused defensive/support build with above average vitality and toughness.

It looks something like this (the PvE version): http://gw2skills.net/editor/?fcEQJAqelspSXHvyuF87IxoCfO0jCjfDL6xjhMlB-jAyAoMhQqBA9JhZwioxWdLiGrSWQWPnU9NGA-e

It’s good at taking some hits, clearing conditions, and providing some extra healing to allies. It’s not spectacular at killing things though, so it might not a be a good way to go if you’re looking to farm in PvE. I’ve really liked using it in dungeons though.

There’s a lot of things to swap out too. You can use HGH instead of potent elixirs, or speedy kits if you want the mobility. I often swap elixir U with elixir R for dungeons, and I use the toolkit in that slot for WvW.

I been able to fight some 1vX in WvW with this build, although it’s generally better at escaping/distracting than it is killing. This build very much kills through attrition, if at all. It definitely hurts not having a stun breaker though, but I do like the elixir gun.

I don’t think 30 in inventions is that common, but there’s some fairly nice defensive trait choices in there. I haven’t mucked around with turrets too much, so I can’t comment on those trait choices.