This is my first post, so I will give a brief intro: I'm an independent general contractor in IL who these days does primary remodels on single family homes that my wife and I buy and sell. For certain jobs I usually contract out the work, because I know some good crews that I can get for cheap (roofing, hanging/taping/mudding sheetrock, etc.), but other jobs I do myself. Plumbing is one of the jobs I usually do myself, because most of my remodels have involved very small jobs (minor repairs, etc.). My current plumbing project though is much more in-depth (see below), but I am still set on doing it myself (primarily to learn, because I hate contracting out a job without knowing the ins and outs). Since my questions are related to more of a DIY type job rather than to contracting, I thought I would post here as opposed to some other forums that I post on.
As to why I am posting, on the first level of the house, there is a room that I am converting to a 3/4 bath and utility room. Since this is my first time doing such a project, I wanted to post a schematic of my DWV plans to get some feedback (see below -- hopefully it is legible, I had to compress it to post, if not ask me for clarification). Some notes: the heights/distances in the image are either FFF or from finished wall; the plumbing is in 2x4 wet walls; studs are reinforced using Simpson SS1.5 (non load-bearing) or HSS2-SDS1.5 (load bearing); the drain/waste slopes @ 1/4"/ft and vents slope toward fixtures @ 1/8"--1/4"/ft; the main stack is 4" cast iron serving a second floor bathroom, and there is a secondary galvanized 2" stack serving the kitchen and a basement utility sink (the latter no longer in use); the tie into the waste will occur in the basement; vent runs V1 and V2 connect out of the page, run up to the second floor via a 2" vent line, and connect to the 2" cast iron vent line serving the second-floor fixtures >6" above their flood-levels, which finally connects to the 4" main stack after another couple of feet; finally, the total developed length of vent pipe of ~30'. Do the plans look reasonable? One thing that I was thinking might have been better though was to use 1-1/2" vent lines (except toilet); will staying with 2" be OK though?