No. With US-based T-Mobile plans, receiving text messages are free in every country (assuming you have unlimited texting in the US), whether or not it's a Simple Choice country for voice or data, and whether or not you even have a Simple Choice plan. Sending texts is what costs $0.50 per, assuming you're not in a Simple Choice country.

Am in Beijing now and phone defaulted to China Mobile and its "E" data. Tried to switch to China Unicom. It would show as selected network but no data. A reboot solved that problem. Now it says "LTE" but is still throttled. Wonder if I got a high speed pack, that it would be high speed?

Yeah but can you get a local SIM for the same price or even less than a high-speed international data pack from TMo?

I remember getting a good 3G SIM from CSL in Hong Kong for $10.

Yes it would be with a high speed pack. Keep in mind ALL data is tunneled via T-Mobile US network - so the performance is as good as China Unicom's backhaul to the US (even if surfing China sites - ALL traffic will route via US) - this also means no China Firewall (Google, Facebook, etc will all work)

Pretty sure that's not right. It's treated just like any other data on their network. In Turkey I encountered a blocked site with a Turkish government notice while roaming.

maybe the proxy-to-US isn't available all the time, or the network does some filtering inbound?

I believe that google detects and changes the google homepage to the localized version, but speedtest/tracert shows the data going back to USA proxy.

It's simply not possible to use direct internet connect on the local network as this would bypass billing and also t-mobile throttling. Likely on the Turkish network packets go through a local inbound filter to block sites once traffic is back and forth to TMO

Is my understanding correct that if I travel abroad (planning to go to India in Jan) - I simply have to turn on my phone and the data speed limit will be enforced automatically due to T-mobile throttling at 128 kbps even though my phone default is set to LTE?

Even if T-mobile partner in India (Airtel) have high speed wireless, I don't have to worry about getting charged for high speed data usage because I won't get those speeds and I have to do nothing special - correct?

yup

if you manage to visit a country not covered by the free 2G data roaming, t-mobile will send you a text, and you have to explicitly turn data on (and get charged $/kb)

T Mobile Global data coverage
 

Well I never turned the data on after one of those texts and some how there is a $12 charge in my account ( I even turned off any chargeable data in my account). Confused

Which phone? Some phones may have issues with background data. If it was turned off on the account than call customer care and asked for it to be removed

I have an iPhone 6 and Simple Choice TMo. I understand I can make free calls via WiFi in France and Netherlands. Would it be advisable to turn off voice mail then? Is that possible? I have no problems with communication with text when not on WiFi. I don't want to come home to a huge bill

Aren't those free wi-fi calls only for calls placed back to the U.S.? I've used that before in Europe since I changed plans but only for calls to the U.S. and it worked fine with no extra charges.

I did have 3 calls to check voice mail on my first international trip and was charged 20 cents per call, each less than a minute, and they went to the Germany number by default (dialed 1-2-3 on the phone when in Germany). I think the workaround there may be to call the 10 digit voice mail phone number in the U.S. while on wi-fi (area code 805). I didn't have any messages on my Hong Kong trip last week to check if that worked.

You can check your voice mail on the web as an option. It's listed under "tools" on your TMobile account page. I just tested that out with a new message and it played back fine and I was able to delete it without any issue. No longer shows on the phone.

Yes, you are correct, calls only back to the US. I don't plan to call any European numbers, and only use text to a friend in AMS. Is there a way to disable VM?

Although it shows in the wiki, I am unable to connect to any network in Thailand other than DTAC or DTAC Trinet (so no AIS or TH GSM for me). And DTAC is terribly slow (not even 2G). Slowest connection I've had anywhere globally :(