actually, Venter inserted a carbon copy of a nucleus of a different species of mycoplasma (genitalium) into a mycoplasma capricolum. Closely related, but not the same species. The work not only showed the viability of fully synthetic dna, but did so while also completely changing the genetic personality of the cell.
The work you cite demonstrates the creation of a wholly new synthetic base pair. You do not need nor want that to make a new life form. The 4 we already have are quite sufficient, and more likely to be biocompatible with human biology. The kind of work needed is much more in line with Venter's. We arent designing space aliens here, we just want a virulent version of tinea that seeks out nervous tissue, and secretes signal hormones when it reaches the brain.
Some additional things that would make it much harder to treat would be the use of a 3 layer cellular membrane instead of 2, genes to detect early precursor molecules to human blood factors (Just past the H antigen stage of blood factor synthesis, where it becomes possible to determine biochemically what blood factor the host is) so that it can synthesize the correct membane antigens to fake out the immune system, and modifications to make use of cholesterol instead of ergosterol.
The argument against individuals seems compelling on the surface, but it conveniently excludes PhD students and other research students from consideration. Such people can leverage social engineering to gain access to the facilities and resources of peers and colleagues, and the acts of ordering the materials and securing the labtime for research projects would not attract attention. There is valid research that could ne done/is needed in regard to human self-antigens and autoimmune disorders caused by environmental and bacterial sources. Such research has synergy with the development of such a thing. The people most likely to be able to carry out something like this are such research students. They are not magically less likely to be sociopaths/psychopaths, and are certainly not immune to being recruited by any number of organizations that may have such interests.
This risk is actually not ignored by many people in that field of academia, and they are actively (right now) petitioning for stronger restrictions on access, just because the primary barriers to such development are being brought low, and they realize the danger that represents.