IDVD or do I need better?

Question

I would like some recommendation for a reasonably savvy user needing to create a DVD of grand child's  third year consisting of an hour's worth of miscellaneous movies from Blackberry phones, Youtube downloads and various cameras.  Usually uses full DVD capacity.
Preamble -
The last one I did I used Adobe Premiere Elements on my Macbook Pro with Mavericks, which  created  a Video_TS folder of four sections.  I then created an ISO image from the folder using Disk Utility and burned the ISO using free download of "Burn".
The resulting DVD burned from ISO presented itself on playing with a menu showing the four sections requiring the user to select the first.  I want a self starting DVD.
Premiere will burn one or more self starting DVDs, but I like to use hard drive files as an intermediary as Premiere takes forever to render the clips for subsequent copies. It also runs my Macbook >700% CPU at >100 degrees C for an hour with fans at full blast.
Questions are
1 -  would I do better to get ILife 11 from ebay and carry out the whole process from the raw  movie clips using ilife components. (The new imovie with mavericks seems to be a toy and can't cope with 100 clips of that size
2 -  will iDVD 11 burn a self starting DVD from the existing Video_TS folder?
3 - Am I deluding myself and do I really need to replace Premiere with a Professional product from Apple Store?
Apple's deprecation of DVD burning is a worry to me, to whom it is still a novelty!

Answer 1

I wholeheartedly second Klaus1's suggestions and recommendations.
Would like to offer these additional suggestions:
Follow this workflow to help assure the best qualty video DVD:
Once you have the project as you want it save it as a disk image via the File ➙ Save as Disk Image  menu option. This will separate the encoding process from the burn process. 
To check the encoding mount the disk image, launch DVD Player and play it.  If it plays OK with DVD Player the encoding is good.
Then burn to disk with Disk Utility or Toast at the slowest speed available (2x-4x) to assure the best burn quality.  Always use top quality media:  Verbatim, Maxell or Taiyo Yuden DVD-R are the most recommended in these forums.
OT