Should I place implants at angles for canines?

Placing the implants at an angle is of no consequence. What you should be considering is the design of the final prosthesis. Then determining where the implants need to go to adequately support the prosthesis in function and aesthetics. Good luck!

Implant needs to be within the triangle of bone which often requires the implant to be tipped palatally to be surrounded by bone.

I agree also. The pt did not attend to get implants, or a roundhouse, they came to get teeth that give aesthetics and function. So plan a prosthesis that will give the pt what they want and then figure out how many implants are required and where. Misch's "Contemporary Implant Dentistry" Vol 2 will give you some excellent rules as to where implants are best placed, both biomechanically and aesthetically. In fact, read the entire 1000+ pages and you will get a good insight into the whole field of implant dentistry. A further thought - why 7 implants ? I hope you have not chosen this number because that is all the pt can afford.

Inclining moderately the implants at the canine site don’t have a major consequence. You must predict the angle of the abutment according to the implant brand you are using: 15˚, 17˚, 20˚, 25˚. You need to ensure good bone thickness at the labial aspect. The issue is the bone shape. You will also need to put another implant of non resorbable material to simulate the canine eminence. This will give a more natural bulky shape to the gum assisting to support the nose.

you need to decide what type of restoration you are making, per above. If you are doing porcelain fused to metal then use 8 implants and make four 3 unit bridges. This eliminates the hassle of trying to get a full arch single unit FPD to passively fit. Also, the porcelain will break over time and you only need to remove a single bridge, not the whole arch. Also, interarch space is not critical with PFM restorations. In fact, more bone is ideal with ceramometal. If you are doing a hybrid then 4-6 implants are all you need, evenly spaced around the arch and significant bone needs to be removed to allow interarch space for abutments, hardware and teeth. These are two totally different restorations with totally different needs in terms of osseous architecture, numbers of implants and implant placement positions. Unfortunately, there are too many practitioners who place implants first and figure out the restorative later. It is absolutely imperative that you know the end result before you even lay a flap. So my question to you is: What do you mean by a "roundhouse"? What material? Cemented to custom abutments or screw retained? What is your bailout plan when the restoration breaks which, I promise you, it will, given time. All these need answers before the implants go in. If you can't answer these questions, stop and enlist the help of a restorative specialist. Stay out of trouble. I'm bailing out dentists all the time who think they can handle big full arch implant cases. These are incredibly difficult! Sorry for the rant but our patients deserves the best we can give them. I wish you luck!