Use to add tobacco with my joints all through my youth. Now in my 30s after giving up cigarettes, I’ve learnt the error of my ways. Adding tobacco is disgusting. Plus it completely messes with the high with all that nasty nicotine, makes it very difficult to tell the difference between indica and sativa.
If you break up the flower correctly or thoroughly with a grinder, there shouldn’t be any issue with it burning evenly or wastage. Also, Raw Black papers (or Raw Organic Hemp) all the way - especially if you want your j to burn evenly all the way through. Rizlas are for heathens.
No cardboard roach/filter tip is not only dangerous because of the amount of high heat going directly into your lungs, it also gets nasty with all that gunk build up matched with your saliva. No cardboard roach is as disgusting as adding tobacco IMO. You get booklets of cardboard filter tips - again Raw does a great job with the perforated edges so you can easily add folds inside the roach. You also get glass filter tips which are reusable. Every single pre-rolled joint I had in the states had cardboard filters in them.