I started a game with a new group. I picked a Kitsune, 3 lvls of rogue and 1 lvl of hunter, planning on adding magus into the mix. Reason for it the people playing the wizard and cleric flip out on some of the others in the group and will not be back.
Your character is not in a good position to multiclass Magus, or any arcane spellcasting class for that matter. It's not enough to just have spellcasting ability, you have to be good at it. Given how many non-caster levels you have already you will never catch up to where you need to be. There's also the serious risk that your base attack bonus is too low; Rogue 3/Hunter 1/Magus 1 has a base attack bonus of only +2. You may as well have just played a single-class Wizard at that point. Your best course of action is to continue as a Hunter and take the Boon Companion feat, adding to the Use Magic Device skill so you can use wands and scrolls to cover spells you don't naturally get access to. If you are an Unchained Rogue, taking the 4th level of Rogue would also be very nice but for classic Rogue there's really nothing more for you there.
If you can rebuild your character, there are a couple of other options available to you. One is the Eldritch Scoundrel archetype, which works very well with the Unchained Rogue. You trade off a lot of Rogue class features, but gain 2/3rds Wizard spellcasting progression. This is a great option for someone who want a balance of Roguery and Wizardy. Another option is the Arcane Trickster. Take 1 level of Rogue to qualify for the Accomplished Sneak Attacker feat, and then take 3 levels of Wizard. This will allow you to begin the path of the Arcane Trickster at the 5th level. This approach emphasizes Wizardry (you will be only 1 level behind a single-class Wizard), but you will have largely competency with weapon attacks.
If you have something more specific in mind for your concept I can try to tailor this further.
Is your GM allowing you to use fractional bonuses? If so, that slightly mitigates one problem with the build, but leaves all the others in place.
The fractional bonus is an optional rule, and you have to confirm with your GM that she is allowing it before you can use it.
I was looking at the unchained book and saw the new rule for baby just not sure how to work the save for the new rules.
I'm not sure what you're asking about here. Unchained Rogue is an upgrade to the Rogue in almost every way, and if your GM allows for it there's no reason not to convert to the Unchained version.
Where is Eldritch Scoundrel found.
It's from the Arcane Anthology.
Is your GM allowing you to use fractional bonuses? If so, that slightly mitigates one problem with the build, but leaves all the others in place.
While I certainly endorse those houserules (was running them long before Unchained made them an official variant rule) not every group follows them and caster level is his biggest problem anyways.