About to install wood flooring and looking at transitions between wood floor and tile as well as a section of hallway flooring that will run perpendicular to main floor.

1. I have three tile sections, entry, kitchen and fireplace (see pics). Assuming the height is pretty flush between tile and wood floor, is T molding required? I assume so to allow expansion and hold down floor, but I have seen many images with a flush install that looks much better. I pulled up a small section of carpet to see check height, it looks pretty flush. But tile is not always at the same exact height, but once I lay my first board, if it looks uneven I can always go with a T mold transition.

2. The main flooring will run from front to back of house, but hallway will run perpendicular. I think it looks better that way, but I’m not 100% opposed to keeping the same direction. I attached some pics I found online that show what I’m thinking of doing. I really don’t want to install T molding since it looks tacky.

Please take look at the pics and let me know your thoughts on transitions from tile to hardwood, and the perpendicular transition at hallway. I personally like the flat transitions and if there is an issue later I can cut them out and install a T-molding transition.... thanks in advance for any advice you can offer.https://www.flickr.com/photos/191675773@N07/shares/Ct90WA

T-molding was invented for laminate floors and some designs of engineered flooring which expand in both directions when used as a floating floor. This gives a small expansion gap between other flooring to accommodate the expansion as the flooring moves.
I never use a T-molding when I install wood flooring that is fastened in place. I have been laying floors for over 40 years. Solid wood flooring does not expand lengthwise. Between wood flooring and tile I leave a gap half the grout width which is then filled with a foam backer rod and sanded caulking colored to match the grout color as floor grout usually has sand in it.
I find that a T-mold will show wear of the finish a lot sooner than the floor next to it and be a constant maintenance problem in the long run.
T-moldings will usually need to be shimmed so they can be fastened correctly, which is another problem.
If you are installing a floating floor, you need a T-molding or bull nose reducer at the edge.

Unfortunately it is floating. Regarding expansion, is it less of an issue with engineered hard wood and weather? I live in Sacramento and the weather is not too extreme. Plus the wall sides will have a 1/4” gap all around. If I go w/o the t molding and see an issue later, can’t I just cut it out and install T molding? Thanks.

So what happens if the flooring decides to shrink? Are you going to fasten the floor where the reducer would have been? The reducer with expansion gap will cover both options.